Methods for inducing an immune response against human immunodeficiency virus infection in subjects undergoing antiretroviral treatment

ABSTRACT

Methods for inducing an immune response against Human Immunodeficiency Virus (HIV) in HIV-infected subjects undergoing antiretroviral therapy (ART) are described. The methods include administering an adenovirus vector primer vaccine and a modified vaccinia virus (MVA) vector booster vaccine encoding mosaic HIV antigens.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No. 15/693,650, filed Sep. 1, 2017, which is entitled to priority pursuant to 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 62/383,140, filed Sep. 2, 2016, the disclosures of which are herein incorporated by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with government support under W81XWH-11-2-0174 awarded by the United States Army Medical Research and Materiel Command. The government has certain rights in this invention.

REFERENCE TO SEQUENCE LISTING SUBMITTED ELECTRONICALLY

This application contains a sequence listing, which is submitted electronically via EFS-Web as an ASCII formatted sequence listing with a file name “Sequence Listing 688097-149”, creation date of Apr. 9, 2019, and having a size of 52.4 kB. The sequence listing submitted via EFS-Web is part of the specification and is herein incorporated by reference in its entirety

BACKGROUND OF THE INVENTION

Globally, an estimated 35.3 million people were living with human immunodeficiency virus (HIV) in 2012, which is an increase from previous years as a result of the wider availability of life-saving antiretroviral therapies (ART). There were 2.3 million new HIV infections globally, representing a 33% decline in the number of new infections from 3.4 million in 2001. At the same time, the number of acquired immunodeficiency syndrome (AIDS) deaths is also declining with 1.6 million AIDS deaths in 2012, down from 2.3 million in 2005. From 1996 to 2012, ART averted 6.6 million AIDS-related deaths worldwide, including 5.5 million deaths in low- and middle-income countries (UNAIDS Report on the Global AIDS Epidemic 2013). In 2012, 9.7 million people in low- and middle-income countries received ART, representing 61% of all who were eligible under the 2010 World Health Organization (WHO) HIV treatment guidelines. However, under the 2013 WHO guidelines, the HIV treatment coverage in low- and middle-income countries represented only 34% of the 28.3 million people eligible in 2013.

Despite its proven success at saving lives, there are significant challenges to initiating and maintaining ART for all of those HIV-infected patients that need it in the world. ART must be taken life-long with near perfect adherence in order to be effective. This places extreme pressure and costs on international donors and over-taxed health systems in developing countries where HIV prevalence rates are highest. Moreover, ART has both short-term and long-term side effects for users, and drug resistance rates rise as more people are on treatment for longer periods of time. Thus, alternative or complementary treatments, including a therapeutic vaccine, which could induce a true or “functional” cure of HIV infection and lessen or eliminate the need for lifelong ART for HIV infected individuals, would therefore be of great benefit.

Studies of HIV vaccine in HIV-uninfected and infected subjects suggest that a successful HIV vaccine program will need to induce immunity against the diverse strains and subtypes that are predominant in the target populations. Improving magnitude, breadth and depth of epitope coverage is thought to be a key to developing a successful T-cell based preventive HIV vaccine. Published primate data indicate that the number of epitope specific responses induced by a vaccine may be an important immune correlate of viral load control in the simian immunodeficiency virus (SIV) challenge system (Chen et al. Nat Med. (2001) 7(11), 1225-31). Strategies to accomplish this include using multivalent vaccines containing immunogens from a number of prevalent subtypes or using mosaic sequences, proteins assembled from natural sequences by in silico recombination, which are optimized for potential T-cell epitopes.

The enhancement of host-mediated clearance of residual virus represents a new additional approach to an HIV functional cure (Carcelain et al. Immunol Rev. (2013) 254(1), 355-71). Findings of several studies have shown the importance of cellular immunity in the control of HIV reservoir size. HIV-1 Gag-specific CD8+ T cells isolated from elite controllers, but not from patients given ART, were shown to kill autologous resting CD4+ T cells in which the virus was reactivated with vorinostat. Moreover, functional anti-viral CD8 T cells are associated with reduced size of the central memory CD4 T cell reservoir in patients controlling their virus without ART. High-avidity multifunctional CD8 cytotoxic T lymphocytes (CTL) that target vulnerable regions in Gag are especially important in limiting virus diversity and reservoirs in individuals infected with HIV who have protective human leukocyte antigen (HLA) class I alleles. Therapeutic vaccines could re-stimulate CD8+ CTL to prevent or control virus relapses and re-establish latent infection in CD4+ T cells after treatment interruptions. A few therapeutic vaccine studies, such as the Ad5 HIV-1 gag vaccine (ACTG A5197 NCT00080106), and infusions of dendritic cells pulsed with inactivated HIV particles have shown transient viral suppression after treatment interruption. Eramune-02 is testing whether a deoxyribonucleic acid (DNA) prime, replication defective, recombinant adenovirus serotype-5 boost strategy, with the Vaccine Research Center's polyvalent HIV-Gag, Pol, Nef, and Env vaccine can reduce the viral reservoir in patients undergoing an ARV-intensification regimen (Katlama Lancet. (2013) 381(9883), 2109-17).

In contrast to patients who initiated ART in the course of chronic HIV infection, many patients who begin ART at the time of acute HIV infection demonstrate blunted or delayed rebound viremia after analytical treatment interruption (ATI) (Gianella et al. Antiviral therapy. (2011) 16(4), 535-45; Goujard et al. (2012) Antiviral therapy. 17(6), 1001-9; Hamlyn et al. (2012) PLoS one. 7(8), e43754; Lodi et al. (2012) Archives of internal medicine. 172(16), 1252-5; Saez-Cirion et al. (2013) PLoS pathogens 9(3), e1003211). Several studies have shown sustained viremic control after treatment interruption in 5%-16% of patients initiated on ART at the time of acute infection (Gianella 2011, supra; Goujard 2012, supra; Grijsen 2012, supra; Lodi 2012, supra; Saez-Cirion 2013, supra). In these studies, factors associated with successful viremic control included shorter duration from HIV onset to ART initiation, longer duration on ART and low PBMC-associated HIV DNA (Williams et al. (2014) Elife 3, e03821).

However, ATI is not the standard of care for HIV infection. The Thai National HIV Treatment Guidelines, recently revised in 2014, now recommend lifelong ART for all persons living with HIV (PLHIV). However, the possibility of safely stopping or interrupting ART would hold great benefit both for patients, who are inconvenienced by having to take medications that require strict adherence and have a number of proven short-term and long-term toxicities, and by national health programs, which are committed to providing medications to hundreds of thousands or even millions of patients for decades to come.

Accordingly, there is a need in the art for improved methods of treating HIV-infected subjects, particularly HIV-infected subjects undergoing antiretroviral therapy (ART), such as therapeutic vaccines. Such a therapeutic vaccine preferably would improve immune responses to HIV and allow treated subjects to discontinue ART while maintaining viremic control.

BRIEF SUMMARY OF THE INVENTION

The invention relates to methods for inducing an immune response against human immunodeficiency virus (HIV) in HIV-infected subjects undergoing antiretroviral therapy (ART) with a primer vaccine of adenovirus 26 (Ad26) vectors encoding mosaic HIV antigens and a booster vaccine of modified vaccinia ankara (MVA) vectors encoding mosaic HIV antigens. Vaccine therapy using an adenovirus primer vaccine and an MVA booster vaccine according to embodiments of the invention among individuals with fully suppressed HIV can result in a measurable immune response and maintain viremic control after ART interruption.

Accordingly, one general aspect of the invention relates to a method of inducing an immune response against a human immunodeficiency virus (HIV) in an HIV-infected human subject undergoing antiretroviral therapy (ART), the method comprising:

-   -   (i) administering to the human subject a primer vaccine         comprising an immunogenically effective amount of one or more         adenovirus 26 (Ad26) vectors encoding one or more mosaic HIV         gag, pol and/or env antigens and a pharmaceutically acceptable         carrier; and     -   (ii) administering to the human subject a booster vaccine         comprising an immunogenically effective amount of one or more         modified vaccinia ankara (MVA) vectors encoding one or more         mosaic HIV gag, pol and/or env antigens and a pharmaceutically         acceptable carrier.

In certain embodiments, the booster vaccine is first administered at about 12-52 weeks after the primer vaccine is initially administered. In certain embodiments the booster vaccine is first administered at about 22-26 weeks, e.g. about 24 weeks, after the primer vaccine is initially administered.

In one embodiment of the invention, the primer vaccine comprises Ad26 vectors encoding one or more mosaic HIV gag, pol and/or env antigens comprising the amino acid sequences selected from the group consisting of SEQ ID NOs: 1, 3, and 4; and the booster vaccine comprises MVA vectors encoding one or more mosaic HIV gag, pol, and/or env antigens comprising the amino acid sequences selected from the group consisting of SEQ ID NOs: 1-4.

In one embodiment of the invention, the primer vaccine comprises Ad26 vectors encoding three mosaic HIV antigens having the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 3, and SEQ ID NO: 4; and the booster vaccine comprises MVA vectors encoding four mosaic HIV antigens having the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, and SEQ ID NO: 4.

In one embodiment of the invention, the primer vaccine is re-administered at about 10-14 weeks after the primer vaccine is initially administered; and the booster vaccine is re-administered at about 46 to 50 weeks after the primer vaccine is initially administered.

In some embodiments, the human subject initiated ART during acute HIV infection.

In a preferred embodiment of the invention, a method of inducing an immune response against a human immunodeficiency virus (HIV) in an HIV-infected human subject undergoing antiretroviral therapy (ART), wherein the human subject initiated ART during acute HIV infection comprises:

-   -   (i) administering to the human subject a primer vaccine         comprising an immunogenically effective amount of one or more         adenovirus 26 (Ad26) vectors encoding one or more mosaic HIV         antigens comprising the amino acid sequences selected from the         group consisting of SEQ ID NOs: 1, 3, and 4 and a         pharmaceutically acceptable carrier; and     -   (ii) administering to the human subject a booster composition         comprising an immunogenically effective amount of one or more         MVA vectors encoding one or more mosaic HIV antigens comprising         the amino acid sequences selected from the group consisting of         SEQ ID NOs: 1-4 and a pharmaceutically acceptable carrier,     -   wherein the primer vaccine is re-administered at about 10-14         weeks after the primer vaccine is initially administered; the         booster vaccine is first administered at about 22-26 weeks after         the primer vaccine is initially administered; and the booster         vaccine is re-administered at about 46-50 weeks after primer         vaccine is initially administered.

In particular embodiments of the invention, the immunogenically effective amount of the Ad26 vectors encoding mosaic HIV antigens of SEQ ID NOs: 1, 3, and 4 consists of three Ad26 vectors of which a first Ad26 vector encodes mosaic HIV antigen of SEQ ID NO: 1, a second Ad26 vector encodes mosaic HIV antigen of SEQ ID NO: 3, and a third Ad26 vector encodes mosaic HIV antigen of SEQ ID NO: 4. In certain embodiments, the first, second, and third Ad26 vectors are administered at a total dose of about 5×10¹⁰ viral particles (vp).

In other particular embodiments of the invention, the immunogenically effective amount of the MVA vectors encoding mosaic HIV antigens of SEQ ID NOs: 1, 2, 3, and 4 consists of two MVA vectors of which a first MVA vector encodes mosaic HIV antigens of SEQ ID NOs: 1 and 3, and a second MVA vector encodes mosaic HIV antigens of SEQ ID NOs: 2 and 4. In certain embodiments, the first and second MVA vectors are administered at a total dose of about 1×10⁸ plaque forming units (pfu).

In other preferred embodiments, the primer vaccine is re-administered at about 12 weeks after the primer vaccine is initially administered, the booster vaccine is first administered at about 24 weeks after the primer vaccine is initially administered, and the booster vaccine is re-administered at about 48 weeks after the primer vaccine is initially administered.

In some embodiments, the ART is discontinued at about 10-14 weeks after the last booster vaccine is administered.

In preferred embodiments, a human subject to which a primer vaccine and a booster vaccine has been administered according to the invention, maintains viral suppression for at least 24 weeks after discontinuing ART.

DETAILED DESCRIPTION OF THE INVENTION

Various publications, articles and patents are cited or described in the background and throughout the specification; each of these references is herein incorporated by reference in its entirety. Discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is for the purpose of providing context for the invention. Such discussion is not an admission that any or all of these matters form part of the prior art with respect to any inventions disclosed or claimed.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention pertains. Otherwise, certain terms used herein have the meanings as set forth in the specification. All patents, published patent applications and publications cited herein are incorporated by reference as if set forth fully herein.

It must be noted that as used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise.

Unless otherwise indicated, the term “at least” preceding a series of elements is to be understood to refer to every element in the series. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the invention.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integer or step. When used herein the term “comprising” can be substituted with the term “containing” or “including” or sometimes when used herein with the term “having”.

When used herein “consisting of” excludes any element, step, or ingredient not specified in the claim element. When used herein, “consisting essentially of” does not exclude materials or steps that do not materially affect the basic and novel characteristics of the claim. Any of the aforementioned terms of “comprising”, “containing”, “including”, and “having”, whenever used herein in the context of an aspect or embodiment of the invention can be replaced with the term “consisting of” or “consisting essentially of” to vary scopes of the disclosure.

As used herein, the conjunctive term “and/or” between multiple recited elements is understood as encompassing both individual and combined options. For instance, where two elements are conjoined by “and/or,” a first option refers to the applicability of the first element without the second. A second option refers to the applicability of the second element without the first. A third option refers to the applicability of the first and second elements together. Any one of these options is understood to fall within the meaning, and therefore satisfy the requirement of the term “and/or” as used herein. Concurrent applicability of more than one of the options is also understood to fall within the meaning, and therefore satisfy the requirement of the term “and/or.”

As used herein, “subject” means a human, who will be or has been treated by a method according to an embodiment of the invention.

The invention relates to methods of priming and boosting an immune response against human immunodeficiency virus (HIV) in an HIV-infected human subject undergoing antiretroviral treatment (ART). According to embodiments of the invention, a primer vaccine and a booster vaccine are administered to the HIV-infected human subject, wherein the primer vaccine comprises an immunogenically effective amount of one or more adenovirus 26 (Ad26) vectors encoding one or more mosaic HIV gag, pol, and/or env antigens; and the booster vaccine comprises an immunogenically effective amount of one or more modified vaccinia ankara (MVA) vectors encoding one or more mosaic HIV gag, pol, and/or env antigens.

Human Immunodeficiency Virus (HIV)

Human immunodeficiency virus (HIV) is a member of the genus Lentivirinae, which is part of the family of Retroviridae. Two species of HIV infect humans: HIV-1 and HIV-2. HIV-1 is the most common strain of HIV virus, and is known to be more pathogenic than HIV-2. As used herein, the terms “human immunodeficiency virus” and “HIV” refer, but are not limited to, HIV-1 and HIV-2. In certain exemplary embodiments, the envelope proteins described herein refer to those present on HIV-1 or HIV-2, preferably on HIV-1.

HIV is categorized into multiple clades with a high degree of genetic divergence. As used herein, the term “HIV Glade” or “HIV subtype” refers to related human immunodeficiency viruses classified according to their degree of genetic similarity. There are currently three groups of HIV-1 isolates: M, N and O. Group M (major strains) consists of at least ten clades, A through J. Group O (outer strains) can consist of a similar number of clades. Group N is a new HIV-1 isolate that has not been categorized in either group M or O.

According to embodiments of the invention, the methods described herein can be used to induce an immune response against one or more clades of HIV.

HIV Antigens

As used herein, the terms “HIV antigen,” “antigenic polypeptide of an HIV,” “HIV antigenic polypeptide,” “HIV antigenic protein,” “HIV immunogenic polypeptide,” and “HIV immunogen” all refer to a polypeptide capable of inducing an immune response, e.g., a humoral and/or cellular mediated response, against HIV in a subject. The HIV antigen can be a protein of HIV, a fragment or epitope thereof, or a combination of multiple HIV proteins or portions thereof, that can induce an immune response against HIV in a subject. An HIV antigen is capable of raising in a host a protective immune response, e.g., inducing an immune response against a viral disease or infection, and/or producing an immunity in (i.e., vaccinates) a subject against a viral disease or infection, that protects the subject against the viral disease or infection. For example, the HIV antigen can comprise a protein or fragment(s) thereof from HIV, such as the HIV gag, pol and env gene products.

According to embodiments of the invention, the HIV antigen can be an HIV-1 or HIV-2 antigen or fragment(s) thereof. Examples of HIV antigens include, but are not limited to gag, pol, and env gene products, which encode structural proteins and essential enzymes. Gag, pol, and env gene products are synthesized as polyproteins, which are further processed into multiple other protein products. The primary protein product of the gag gene is the viral structural protein gag polyprotein, which is further processed into MA, CA, SP1, NC, SP2, and P6 protein products. The pol gene encodes viral enzymes (Pol, polymerase), and the primary protein product is further processed into RT, RNase H, IN, and PR protein products. The env gene encodes structural proteins, specifically glycoproteins of the virion envelope. The primary protein product of the env gene is gp160, which is further processed into gp120 and gp41. A heterologous nucleic acid sequence according to the invention preferably encodes a gag, env, and/or pol gene product, or portion thereof.

According to embodiments of the invention, an HIV antigen is a mosaic HIV antigen. As used herein, “mosaic antigen” refers to a recombinant protein assembled from fragments of natural sequences. The “mosaic antigen” can be computationally generated and optimized using a genetic algorithm. Mosaic antigens resemble natural antigens, but are optimized to maximize the coverage of potential T-cell epitopes found in the natural sequences, which improves the breadth and coverage of the immune response.

A “mosaic HIV antigen” according to the invention is a mosaic HIV gag, env, or pol antigen, or any portion or combination thereof, more preferably a mosaic HIV-1 gag, env, or pol antigen, or any portion or combination thereof. Mosaic HIV gag, env, and/or pol antigens are mosaic antigens comprising multiple epitopes derived from one or more of the gag, pol and env polyprotein sequences of HIV. The epitope sequences of the mosaic HIV gag, pol, and/or env antigens according to the invention resemble the sequences of the natural HIV antigens, but are optimized to present a broader possible array of T cell epitopes to improve coverage of epitopes found in circulating HIV sequences.

For example, to provide maximal coverage of potential T-cell epitopes, mosaic gag, pol, and env antigens are designed to provide optimal coverage of one or more HIV clades. Sequence Database in silico recombinant sequences of fragments of 9 contiguous amino acids (9-mers) are selected that resemble real proteins and that maximize the number of 9-mer sequence matches between vaccine candidates and the global database. The mosaic HIV gag, pol, and env antigens have similar domain structure to natural antigens and consist entirely of natural sequences with no artificial junctions. The pol antigens can contain mutants to eliminate catalytic activity. The monomeric env gp140 mosaic antigens can contain point mutations to eliminate cleavage and fusion activity.

In one embodiment, a mosaic HIV antigen is a mosaic HIV gag antigen comprising epitopes derived from the sequences of gag gene products; a mosaic HIV pol antigen comprising epitopes derived from the sequences of pol gene products; or a mosaic HIV env antigen comprising epitopes derived from the sequences of env gene products.

In other embodiments, a mosaic HIV antigen according to the invention comprises a combination of epitopes derived from sequences of gag, pol, and/or env gene products. Illustrative and non-limiting examples include mosaic env-pol antigens with epitopes derived from the sequences of env and pol gene products; mosaic env-gag antigens with epitopes derived from the sequences of env and gag gene products; mosaic gag-pol antigens with epitopes derived from the sequences of gag and pol gene products; and mosaic gag-env antigens with epitopes derived from the sequences of gag and env gene products.

According to embodiments of the invention, the mosaic HIV gag, pol, and/or env antigens can comprise a combination of epitopes derived from sequences of gag, pol, and env gene products from one or more clades.

Examples of mosaic HIV Gag-Pol-Env antigens include those described in, e.g., US20120076812, Barouch et al., Nat Med 2010, 16:319-323; Barouch et al., Cell 155:1-9, 2013, all of which are incorporated herein by reference in their entirety. In certain embodiments of the invention, the mosaic HIV antigens encoded by the vectors comprise the amino acid sequences selected from the group consisting of SEQ ID NOs: 1-4. Alternative and/or additional HIV antigens could be encoded by the primer vaccine and/or the booster vaccine of the invention in certain embodiments, e.g. to further broaden the immune response.

In view of the present disclosure, a mosaic HIV antigen can be produced using methods known in the art. See, e.g., US20120076812, Fischer et al, Nat Med, 2007. 13(1): p. 100-6; Barouch et al., Nat Med 2010, 16:319-323, all of which are incorporated herein by reference in their entirety.

Adenovirus Vector

Primer vaccines used in the methods of the invention comprise one or more adenovirus vectors, particularly human adenovirus 26 vectors encoding one more HIV antigens, e.g., mosaic HIV antigens, for instance mosaic HIV gag, pol, and/or env antigens. As used herein, the notation “rAd” means recombinant adenovirus, e.g., “rAd26” refers to recombinant human adenovirus 26.

An advantage of human adenovirus serotype 26 is a low seroprevalence and/or low pre-existing neutralizing antibody titers in the human population. In some embodiments, the adenovirus vector is a replication deficient recombinant viral vector, such as a replication deficient recombinant adenovirus 26 vector.

An “adenovirus capsid protein” refers to a protein on the capsid of an adenovirus (e.g., Ad26 vectors) that is involved in determining the serotype and/or tropism of a particular adenovirus. Adenoviral capsid proteins typically include the fiber, penton and/or hexon proteins. An rAd26 vector comprises at least the hexon of Ad26, preferably at least the hexon and fiber of Ad26. In preferred embodiments, the hexon, penton and fiber are of Ad26. Preferably, also the non-capsid proteins are from Ad26.

In certain embodiments, the recombinant adenovirus vector useful in the invention is derived mainly or entirely from Ad26 (i.e., the vector is rAd26). In some embodiments, the adenovirus is replication deficient, e.g., because it contains a deletion in the E1 region of the genome. For the adenoviruses derived from Ad26 used in the invention, it is typical to exchange the E4-orf6 coding sequence of the adenovirus with the E4-orf6 of an adenovirus of human subgroup C such as Ad5. This allows propagation of such adenoviruses in well-known complementing cell lines that express the E1 genes of Ad5, such as for example 293 cells, PER.C6 cells, and the like (see, e.g. Havenga, et al., 2006, J Gen Virol 87: 2135-43; WO 03/104467). However, such adenoviruses will not be capable of replicating in non-complementing cells that do not express the E1 genes of Ad5. Thus, in certain embodiments, the adenovirus is a human adenovirus of serotype 26, with a deletion in the E1 region into which the nucleic acid encoding one or more mosaic HIV antigens has been cloned, and with an E4 orf6 region of Ad5.

The preparation of recombinant adenoviral vectors is well known in the art. Preparation of rAd26 vectors is described, for example, in WO 2007/104792 and in Abbink et al., (2007) Virol 81(9): 4654-63, both of which are incorporated by reference herein in their entirety. Exemplary genome sequences of Ad26 are found in GenBank Accession EF 153474 and in SEQ ID NO: 1 of WO 2007/104792.

Typically, an adenovirus vector useful in the invention is produced using a nucleic acid comprising the entire recombinant adenoviral genome (e.g., a plasmid, cosmid, or baculovirus vector).

The adenovirus vectors useful in the invention are typically replication deficient. In these embodiments, the virus is rendered replication deficient by deletion or inactivation of regions critical to replication of the virus, such as the E1 region. The regions can be substantially deleted or inactivated by, for example, inserting a gene of interest, such as a gene encoding an HIV antigen (usually linked to a promoter) within the region. In some embodiments, the vectors of the invention can contain deletions in other regions, such as the E3 region, or insertions of heterologous genes linked to a promoter within such regions. Mutations in the E3 region of the adenovirus need not be complemented by the cell line, since E3 is not required for replication.

A packaging cell line is typically used to produce sufficient amounts of adenovirus vectors for use in the invention. A packaging cell is a cell that comprises those genes that have been deleted or inactivated in a replication deficient vector, thus allowing the virus to replicate in the cell. Suitable packaging cell lines include, for example, PER.C6, 911, and HEK293.

According to embodiments of the invention, any mosaic HIV gag, pol and/or env antigen can be expressed in the adenovirus 26 vectors described herein. Optionally, the heterologous gene encoding the mosaic HIV antigen can be codon-optimized to ensure proper expression in the treated host (e.g., human). Codon-optimization is a technology widely applied in the art. Typically, the heterologous gene encoding the mosaic HIV antigen is cloned into the E1 and/or the E3 region of the adenoviral genome. Non-limiting embodiments of codon optimized nucleotide sequences encoding HIV antigens with SEQ ID NOs: 1-4, respectively, are provided herein as SEQ ID NOs: 5-8, respectively.

In a preferred embodiment of the invention, one or more adenovirus 26 (Ad26) vectors comprise nucleic acid that encodes one or more mosaic HIV env, gag, and/or pol antigens. In other preferred embodiments, the one or more Ad26 vectors encode one or more mosaic HIV antigens comprising the amino acid sequences selected from the group consisting of SEQ ID NOs: 1-4, and more preferably encode three mosaic HIV antigens having the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 3, and SEQ ID NO: 4.

The heterologous gene encoding the mosaic HIV antigen can be under the control of (i.e., operably linked to) an adenovirus-derived promoter (e.g., the Major Late Promoter), or can be under the control of a heterologous promoter. Examples of suitable heterologous promoters include the cytomegalovirus (CMV) promoter and the Rous sarcoma virus (RSV) promoter. Preferably, the promoter is located upstream of the heterologous gene encoding the mosaic HIV antigen within an expression cassette. In a preferred embodiment, the heterologous promoter is a CMV promoter.

MVA Vectors

Booster vaccines used in the methods of the invention comprise one or more Modified Vaccinia Ankara (MVA) vectors encoding one more HIV antigens, e.g., mosaic HIV antigens, for instance mosaic HIV gag, pol, and/or env antigens. MVA vectors useful in the invention utilize attenuated virus derived from MVA virus, which is characterized by the loss of their capabilities to reproductively replicate in human cell lines. The MVA vectors can express any mosaic HIV antigen known to those of skill in the art, including but not limited to the mosaic HIV antigens discussed herein, such as the mosaic HIV gag, pol, and/or env antigens.

MVA has been generated by more than 570 serial passages on chicken embryo fibroblasts of the dermal vaccinia strain Ankara (Chorioallantois vaccinia virus Ankara virus, CVA; for review see Mayr et al. (1975) Infection 3, 6-14) that was maintained in the Vaccination Institute, Ankara, Turkey for many years and used as the basis for vaccination of humans. However, due to the often severe post-vaccination complications associated with vaccinia viruses, there were several attempts to generate a more attenuated, safer smallpox vaccine.

During the period of 1960 to 1974, Prof. Anton Mayr succeeded in attenuating CVA by over 570 continuous passages in CEF cells (Mayr et al. (1975), Infection 3, 6-14). It was shown in a variety of animal models that the resulting MVA was avirulent (Mayr, A. & Danner, K. (1978), Dev. Biol. Stand. 41: 225-234). As part of the early development of MVA as a pre-smallpox vaccine, there were clinical trials using MVA-517 in combination with Lister Elstree (Stickl (1974), Prev. Med. 3: 97-101; Stickl and Hochstein-Mintzel (1971), Munch. Med. Wochenschr. 113: 1149-1153) in subjects at risk for adverse reactions from vaccinia. In 1976, MVA derived from MVA-571 seed stock (corresponding to the 571st passage) was registered in Germany as the primer vaccine in a two-stage parenteral smallpox vaccination program. Subsequently, MVA-572 was used in approximately 120,000 Caucasian individuals, the majority children between 1 and 3 years of age, with no reported severe side effects, even though many of the subjects were among the population with high risk of complications associated with vaccinia (Mayr et al. (1978), Zentralbl. Bacteriol. (B) 167:375-390). MVA-572 was deposited at the European Collection of Animal Cell Cultures as ECACC V94012707.

As a result of the passaging used to attenuate MVA, there are a number of different strains or isolates, depending on the number of passages conducted in CEF cells. For example, MVA-572 was used in a small dose as a pre-vaccine in Germany during the smallpox eradication program, and MVA-575 was extensively used as a veterinary vaccine. MVA as well as MVA-BN lacks approximately 15% (31 kb from six regions) of the genome compared with ancestral CVA virus. The deletions affect a number of virulence and host range genes, as well as the gene for Type A inclusion bodies. MVA-575 was deposited on Dec. 7, 2000, at the European Collection of Animal Cell Cultures (ECACC) under Accession No. V00120707. The attenuated CVA-virus MVA (Modified Vaccinia Virus Ankara) was obtained by serial propagation (more than 570 passages) of the CVA on primary chicken embryo fibroblasts.

Even though Mayr et al. demonstrated during the 1970s that MVA is highly attenuated and avirulent in humans and mammals, certain investigators have reported that MVA is not fully attenuated in mammalian and human cell lines since residual replication might occur in these cells (Blanchard et al. (1998), J. Gen. Virol. 79:1159-116779; Carroll & Moss (1997), Virology 238:198-211; U.S. Pat. No. 5,185,146; 81). It is assumed that the results reported in these publications have been obtained with various known strains of MVA, since the viruses used essentially differ in their properties, particularly in their growth behavior in various cell lines. Such residual replication is undesirable for various reasons, including safety concerns in connection with use in humans.

Strains of MVA having enhanced safety profiles for the development of safer products, such as vaccines or pharmaceuticals, have been developed, for example by Bavarian Nordic. MVA was further passaged by Bavarian Nordic and is designated MVA-BNA. A representative sample of MVA-BN was deposited on Aug. 30, 2000 at the European Collection of Cell Cultures (ECACC) under Accession No. V00083008. MVA-BN is further described in WO 02/42480 (US 2003/0206926) and WO 03/048184 (US 2006/0159699), both of which are incorporated by reference herein in their entirety.

“Derivatives” or “variants” of MVA refer to viruses exhibiting essentially the same replication characteristics as MVA as described herein, but exhibiting differences in one or more parts of their genomes. For example, MVA-BN as well as a derivative or variant of MVA-BN fails to reproductively replicate in vivo in humans and mice, even in severely immune suppressed mice. More specifically, MVA-BN or a derivative or variant of MVA-BN has preferably also the capability of reproductive replication in chicken embryo fibroblasts (CEF), but no capability of reproductive replication in the human keratinocyte cell line HaCat (Boukamp et al (1988), J. Cell Biol. 106: 761-771), the human bone osteosarcoma cell line 143B (ECACC Deposit No. 91112502), the human embryo kidney cell line 293 (ECACC Deposit No. 85120602), and the human cervix adenocarcinoma cell line HeLa (ATCC Deposit No. CCL-2). Additionally, a derivative or variant of MVA-BN has a virus amplification ratio at least two fold less, more preferably three-fold less than MVA-575 in Hela cells and HaCaT cell lines. Tests and assays for these properties of MVA variants are described in WO 02/42480 (US 2003/0206926) and WO 03/048184 (US 2006/0159699).

The term “not capable of reproductive replication” or “no capability of reproductive replication” is, for example, described in WO 02/42480, which also teaches how to obtain MVA having the desired properties as mentioned above. The term applies to a virus that has a virus amplification ratio at 4 days after infection of less than 1 using the assays described in WO 02/42480 or in U.S. Pat. No. 6,761,893, both of which are incorporated by reference herein in their entirety.

The term “fails to reproductively replicate” refers to a virus that has a virus amplification ratio at 4 days after infection of less than 1. Assays described in WO 02/42480 or in U.S. Pat. No. 6,761,893 are applicable for the determination of the virus amplification ratio.

The amplification or replication of a virus is normally expressed as the ratio of virus produced from an infected cell (output) to the amount originally used to infect the cell in the first place (input), and is referred to as the “amplification ratio.” An amplification ratio of “1” defines an amplification status where the amount of virus produced from the infected cells is the same as the amount initially used to infect the cells, meaning that the infected cells are permissive for virus infection and reproduction. In contrast, an amplification ratio of less than 1, i.e., a decrease in output compared to the input level, indicates a lack of reproductive replication and therefore attenuation of the virus.

The advantages of MVA-based vaccine include their safety profile as well as availability for large scale vaccine production. Furthermore, in addition to its efficacy, the feasibility of industrial scale manufacturing can be beneficial. Additionally, MVA-based vaccines can deliver multiple heterologous antigens and allow for simultaneous induction of humoral and cellular immunity.

MVA vectors useful for the invention can be prepared using methods known in the art, such as those described in WO/2002/042480, WO/2002/24224, US20110159036, U.S. Pat. No. 8,197,825, etc., the relevant disclosures of which are incorporated herein by references.

In another aspect, replication deficient MVA viral strains can also be suitable for use in the invention, such as strains MVA-572 and MVA-575, or any other similarly attenuated MVA strain. Also suitable can be a mutant MVA, such as the deleted chorioallantois vaccinia virus Ankara (dCVA). A dCVA comprises del I, del II, del III, del IV, del V, and del VI deletion sites of the MVA genome. The sites are particularly useful for the insertion of multiple heterologous sequences. The dCVA can reproductively replicate (with an amplification ratio of greater than 10) in a human cell line (such as human 293, 143B, and MRC-5 cell lines), which then enable the optimization by further mutation useful for a virus-based vaccination strategy (see, e.g., WO 2011/092029).

In a preferred embodiment of the invention, the one or more MVA vectors comprise a nucleic acid that encodes one or more mosaic HIV env, gag, and/or pol antigens. In other preferred embodiments, the one or more MVA vectors encode one or more mosaic HIV antigens comprising the amino acid sequences selected from the group consisting of SEQ ID NOs: 1-4, and more preferably encode four mosaic HIV antigens having the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, and SEQ ID NO: 4.

Nucleic acid sequences encoding the mosaic HIV antigens can be inserted into one or more intergenic regions (IGR) of the MVA. In certain embodiments, the IGR is selected from IGR07/08, IGR 44/45, IGR 64/65, IGR 88/89, IGR 136/137, and IGR 148/149. In certain embodiments, less than 5, 4, 3, or 2 IGRs of the recombinant MVA comprise heterologous nucleotide sequences encoding an HIV antigen, such as a mosaic HIV antigen. The heterologous nucleotide sequences can, additionally or alternatively, be inserted into one or more of the naturally occurring deletion sites, in particular into the main deletion sites I, II, III, IV, V, or VI of the MVA genome. In certain embodiments, less than 5, 4, 3, or 2 of the naturally occurring deletion sites of the recombinant MVA comprise heterologous nucleotide sequences encoding mosaic HIV antigens.

The number of insertion sites of MVA comprising heterologous nucleotide sequences encoding HIV antigens can be 1, 2, 3, 4, 5, or more. In certain embodiments, the heterologous nucleotide sequences are inserted into 4, 3, 2, or fewer insertion sites. Preferably, two insertion sites are used. In certain embodiments, three insertion sites are used. Preferably, the recombinant MVA comprises at least 2, 3, 4, 5, 6, or 7 genes inserted into 2 or 3 insertion sites.

The recombinant MVA viruses provided herein can be generated by routine methods known in the art. Methods to obtain recombinant poxviruses or to insert exogenous coding sequences into a poxviral genome are well known to the person skilled in the art. For example, methods for standard molecular biology techniques such as cloning of DNA, DNA and RNA isolation, Western blot analysis, RT-PCR and PCR amplification techniques are described in Molecular Cloning, A laboratory Manual (2nd Ed.) (J. Sambrook et al., Cold Spring Harbor Laboratory Press (1989)), and techniques for the handling and manipulation of viruses are described in Virology Methods Manual (B. W. J. Mahy et al. (eds.), Academic Press (1996)). Similarly, techniques and know-how for the handling, manipulation and genetic engineering of MVA are described in Molecular Virology: A Practical Approach (A. J. Davison & R. M. Elliott (Eds.), The Practical Approach Series, IRL Press at Oxford University Press, Oxford, UK (1993) (see, e.g., Chapter 9: Expression of genes by Vaccinia virus vectors)) and Current Protocols in Molecular Biology (John Wiley & Son, Inc. (1998) (see, e.g., Chapter 16, Section IV: Expression of proteins in mammalian cells using vaccinia viral vector)).

For the generation of the various recombinant MVAs disclosed herein, different methods can be applicable. The DNA sequence to be inserted into the virus can be placed into an E. coli plasmid construct into which DNA homologous to a section of DNA of the MVA has been inserted. Separately, the DNA sequence to be inserted can be ligated to a promoter. The promoter-gene linkage can be positioned in the plasmid construct so that the promoter-gene linkage is flanked on both ends by DNA homologous to a DNA sequence flanking a region of MVA DNA containing a non-essential locus. The resulting plasmid construct can be amplified by propagation within E. coli bacteria and isolated. The isolated plasmid containing the DNA gene sequence to be inserted can be transfected into a cell culture, e.g., of chicken embryo fibroblasts (CEFs), at the same time the culture is infected with MVA. Recombination between homologous MVA DNA in the plasmid and the viral genome, respectively, can generate an MVA modified by the presence of foreign DNA sequences.

According to a preferred embodiment, a cell of a suitable cell culture such as, e.g., CEF cells, can be infected with a poxvirus. The infected cell can be, subsequently, transfected with a first plasmid vector comprising a foreign or heterologous gene or genes, preferably under the transcriptional control of a poxvirus expression control element. As explained above, the plasmid vector also comprises sequences capable of directing the insertion of the exogenous sequence into a selected part of the poxviral genome. Optionally, the plasmid vector also contains a cassette comprising a marker and/or selection gene operably linked to a poxviral promoter.

Suitable marker or selection genes are, e.g., the genes encoding the green fluorescent protein, β-galactosidase, neomycin-phosphoribosyltransferase or other markers. The use of selection or marker cassettes simplifies the identification and isolation of the generated recombinant poxvirus. However, a recombinant poxvirus can also be identified by PCR technology. Subsequently, a further cell can be infected with the recombinant poxvirus obtained as described above and transfected with a second vector comprising a second foreign or heterologous gene or genes. In case, this gene shall be introduced into a different insertion site of the poxviral genome, the second vector also differs in the poxvirus-homologous sequences directing the integration of the second foreign gene or genes into the genome of the poxvirus. After homologous recombination has occurred, the recombinant virus comprising two or more foreign or heterologous genes can be isolated. For introducing additional foreign genes into the recombinant virus, the steps of infection and transfection can be repeated by using the recombinant virus isolated in previous steps for infection and by using a further vector comprising a further foreign gene or genes for transfection.

Alternatively, the steps of infection and transfection as described above are interchangeable, i.e., a suitable cell can at first be transfected by the plasmid vector comprising the foreign gene and, then, infected with the poxvirus. As a further alternative, it is also possible to introduce each foreign gene into different viruses, co-infect a cell with all the obtained recombinant viruses and screen for a recombinant including all foreign genes. A third alternative is ligation of DNA genome and foreign sequences in vitro and reconstitution of the recombined vaccinia virus DNA genome using a helper virus. A fourth alternative is homologous recombination in E. coli or another bacterial species between a vaccinia virus genome cloned as a bacterial artificial chromosome (BAC) and a linear foreign sequence flanked with DNA sequences homologous to sequences flanking the desired site of integration in the vaccinia virus genome.

The heterologous nucleic acid encoding one or more mosaic HIV antigens can be under the control of (i.e., operably linked to) one or more poxvirus promoters. In certain embodiments, the poxvirus promoter is a Pr7.5 promoter, a hybrid early/late promoter, or a PrS promoter, a PrS5E promoter, a synthetic or natural early or late promoter, or a cowpox virus ATI promoter.

In certain embodiments, a first MVA vector expresses antigens having SEQ ID NO:1 and SEQ ID NO: 3, and a second MVA vector expresses antigens having SEQ ID NO: 2 and SEQ ID NO: 4.

Immunogenic Compositions

Immunogenic compositions are compositions comprising an immunogenically effective amount of a purified or partially purified adenovirus 26 or MVA vector for use in the invention. A vector can encode one mosaic HIV antigen or multiple mosaic HIV antigens, such as mosaic HIV gag, pol, and/or env antigens. The adenovirus 26 and MVA vectors can encode any mosaic HIV gag, pol, and/or env antigen in view of the present disclosure. The one or more mosaic HIV antigens encoded by the adenovirus 26 vector can be the same or different as the one or more mosaic HIV antigens encoded by the MVA vector. Said compositions can be formulated as a vaccine (also referred to as an “immunogenic composition”), such as a primer vaccine or a booster vaccine, according to methods well known in the art. Such compositions can include adjuvants to enhance immune responses. The optimal ratios of each component in the formulation can be determined by techniques well known to those skilled in the art in view of the present disclosure.

As used herein, “an immunogenically effective amount” or “immunologically effective amount” means an amount of a composition or vector sufficient to induce a desired immune effect or immune response in a subject in need thereof. In one embodiment, an immunogenically effective amount means an amount sufficient to induce an immune response in a subject in need thereof. In another embodiment, an immunogenically effective amount means an amount sufficient to produce immunity in a subject in need thereof, e.g., provide a therapeutic effect against a disease such as HIV infection. An immunogenically effective amount can vary depending upon a variety of factors, such as the physical condition of the subject, age, weight, health, etc. An immunogenically effective amount can readily be determined by one of ordinary skill in the art in view of the present disclosure.

As general guidance, an immunogenically effective amount when used with reference to a recombinant viral vector can range from about 10⁶ viral particles (vps) or plaque forming units (pfus) to about 10¹² viral particles or plaque forming unites, for example 10⁶, 10⁷, 10⁸, 10⁹, 10¹⁰, 10¹¹, or 10¹² viral particles or plaque forming units. An immunogenically effective amount can be administered in a single composition, or in multiple compositions, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 compositions (e.g., tablets, capsules or injectable), wherein the administration of the multiple tablets, capsules or injections collectively provides a subject with the immunogenically effective amount. It is also possible to administer an immunogenically effective amount to a subject, and subsequently administer another dose of an immunogenically effective amount to the same subject, in a so-called prime-boost regimen. This general concept of a prime-boost regimen is well known to the skill person in the vaccine field. Further booster administrations can optionally be added to the regimen, as needed.

In one embodiment, an immunogenic composition is a primer vaccine used for priming an immune response. According to embodiments of the invention, a primer vaccine comprises an immunogenically effective amount of one or more adenovirus 26 (Ad26) vectors encoding one or more mosaic HIV gag, pol, and/or env antigens and a pharmaceutically acceptable carrier. In some embodiments, the Ad26 vectors encode one or more mosaic HIV antigens comprising the amino acid sequences selected from the group consisting of SEQ ID NOs: 1, 3 and 4. In some embodiments, the Ad26 vectors encode three mosaic HIV antigens having the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 3, and SEQ ID NO: 4. The mosaic HIV antigens can be encoded by the same Ad26 vector or different Ad26 vector, such as one, two, three, four or more Ad26 vectors.

The immunogenically effective amount of the one or more Ad26 vectors can be about 10⁸, 10⁹, 10¹⁰, 10¹¹, or 10¹² viral particles (vps), preferably about 10⁹ to 10¹¹ viral particles, and more preferably about 10¹⁰ viral particles, such as for instance about 0.5×10¹⁰, 1×10¹⁰, 2×10¹⁰, 3×10¹⁰, 4×10¹⁰, 5×10¹⁰, 6×10¹⁰, 7×10¹⁰, 8×10¹⁰, 9×10¹⁰, or 10×10¹⁰ viral particles. In certain embodiments, the immunogenically effective amount is about 5×10¹⁰ viral particles, such that the one or more Ad26 vectors are administered at a total dose of about 5×10¹⁰ viral particles.

A primer vaccine for use in the invention can comprise one Ad26 vector, or multiple Ad26 vectors, such as 2, 3, 4, or more Ad26 vectors, encoding the same or different mosaic HIV gag, pol, and/or env antigens. Thus, an immunogenically effective amount can be from one Ad26 vector or multiple Ad26 vectors. For example, a total administered dose of about 10⁸ to 10¹² viral particles, such as for instance about 5×10¹⁰ viral particles, in the primer vaccine can be from three Ad26 vectors each encoding a different mosaic HIV antigen, such as those shown in SEQ ID NOs: 1, 3, and 4.

In a particular embodiment, the immunogenically effective amount of Ad26 vectors encoding SEQ ID NOs: 1, 3, and 4 consists of three Ad26 vectors of which a first Ad26 vector encodes mosaic HIV antigen of SEQ ID NO: 1, a second Ad26 vector encodes mosaic HIV antigen of SEQ ID NO: 3, and a third Ad26 vector encodes mosaic HIV antigen sequence of SEQ ID NO: 4. Preferably, the first, second, and third Ad26 vectors are administered at a total dose of about 10¹⁰-10¹¹ viral particles, for instance about 5×10¹⁰ viral particles.

According to embodiments of the invention, when a primer vaccine comprises more than one Ad26 vector, the Ad26 vectors can be included in the composition in any ratio to achieve the desired immunogenically effective amount. As an illustrative and non-limiting example, two Ad26 vectors can be included in a ratio of about 1:2, 1:1, or 2:1; and three Ad26 vectors consisting of a first, second, and third Ad26 vector can in non-limiting exemplary embodiments be included in a ratio of about 1:1:1, 1:1:2, 1:2:1, or 2:1:1, respectively. In a particular embodiment, a primer vaccine comprises three Ad26 vectors consisting of a first, second, and third Ad26 vector encoding mosaic HIV antigens of SEQ ID NO: 1, SEQ ID NO: 3 and SEQ ID NO: 4, respectively, at a ratio of about 2:1:1.

In another embodiment, an immunogenic composition is a booster vaccine. According to embodiments of the invention, a booster vaccine comprises an immunogenically effective amount of one or more MVA vectors encoding one or more mosaic HIV gag, pol, and/or env antigens and a pharmaceutically acceptable carrier. In some embodiments, the MVA vectors encode one or more mosaic HIV antigens comprising the amino acid sequences selected from the group consisting of SEQ ID NOs: 1-4. In other embodiments, the MVA vectors encode four mosaic HIV antigens having the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, and SEQ ID NO: 4. The mosaic HIV antigens can be encoded by the same MVA vector, or different MVA vectors, such as one, two, three, four or more MVA vectors.

The immunogenically effective amount of the one or more MVA vectors in the booster vaccine can be about 10⁶, 10⁷, 10⁸, 10⁹, or 10¹⁰ plaque forming units (pfus), preferably about 10⁷ to 10⁹ pfus, and more preferably about 10⁸ pfus, such as for instance about 0.5×10⁸, 1×10⁸, 2×10⁸, 3×10⁸, 4×10⁸, or 5×10⁸ pfus. In certain embodiments, the immunogenically effective amount is about 1×10⁸ pfus, such that the one or more MVA vectors are administered at a total dose of about 1×10⁸ pfus.

A booster vaccine for use in the invention can comprise one MVA vector, or multiple MVA vectors, such as 2, 3, 4, or more MVA vectors, encoding the same or different mosaic HIV gag, pol, and/or env antigens. Thus, an immunogenically effective amount can be from one MVA vector or multiple MVA vectors. For example, a total administered dose of about 10⁶ to 10¹⁰ pfus, such as for instance about 1×10⁸ pfus, in the booster vaccine can be from two MVA vectors each encoding different mosaic HIV antigens, such as those shown in SEQ ID NOs: 1, 2, 3, and 4.

In a particular embodiment, the immunogenically effective amount of MVA vectors encoding SEQ ID NOs: 1, 2, 3, and 4 consists of two MVA vectors of which a first MVA vector encodes mosaic HIV antigens of SEQ ID NOs: 1 and 3, and a second MVA vector encodes mosaic HIV antigens of SEQ ID NOs: 2 and 4. Preferably, the first and second MVA vectors are administered at a total dose of about 10⁸ pfus, for instance about 1×10⁸ pfus.

According to embodiments of the invention, when a booster vaccine comprises more than one MVA vector, the MVA vectors can be included in the composition in any ratio to achieve the desired immunogenically effective amount. As an illustrative and non-limiting example, two MVA vectors can be included in a ratio of about 1:2, 1:1, or 2:1. In a particular embodiment, a primer vaccine comprises two MVA vectors consisting of a first MVA vector encoding mosaic HIV antigens of SEQ ID NOs: 1 and 3, and a second MVA vector encoding mosaic HIV antigens of SEQ ID NOs: 2 and 4 at a ratio of about 1:1.

The preparation and use of immunogenic compositions are well known to those of ordinary skill in the art. Liquid pharmaceutical compositions generally include a liquid carrier such as water, petroleum, animal or vegetable oils, mineral oil or synthetic oil. Physiological saline solution, dextrose or other saccharide solution or glycols such as ethylene glycol, propylene glycol or polyethylene glycol can also be included. The immunogenic compositions used in the invention, e.g., primer vaccines and booster vaccines, can be formulated for administration according to any method known in the art in view of the present disclosure, and are preferably formulated for intramuscular administration.

In addition to the adenovirus 26 or MVA vectors encoding the one or more mosaic HIV gag, pol, and/or env antigens, the priming and/or boosting immunizations can comprise other antigens. The other antigens used in combination with the adenovirus 26 and/or MVA vectors are not critical to the invention and can be, for example, other HIV antigens and nucleic acids expressing them.

The immunogenic compositions useful in the invention can further optionally comprise adjuvants. Adjuvants suitable for co-administration in accordance with the invention should be ones that are potentially safe, well tolerated and effective in people. Non-limiting examples include QS-21, Detox-PC, MPL-SE, MoGM-CSF, TiterMax-G, CRL-1005, GERBU, TERamide, PSC97B, Adjumer, PG-026, GSK-I, GcMAF, B-alethine, MPC-026, Adjuvax, CpG ODN, Betafectin, Aluminium salts such as Aluminium Phosphate (e.g. AdjuPhos) or Aluminium Hydroxide, and MF59.

The immunogenic compositions used for priming and boosting an immune response according to embodiments of the invention comprise a pharmaceutically acceptable carrier, such as a pharmaceutically acceptable excipient, carrier, buffer, stabilizer or other materials well known to those skilled in the art. Such materials should be non-toxic and should not interfere with the efficacy of the active ingredient. The precise nature of the carrier or other material can depend on the route of administration, e.g., intramuscular, subcutaneous, oral, intradermal, cutaneous, intramucosal (e.g., gut), intranasal or intraperitoneal routes. Preferably, the pharmaceutically acceptable carrier included in the primer and booster vaccines is suitable for intramuscular administration.

Method of Inducing an Immune Response

The invention provides a method of priming and boosting an immune response against a human immunodeficiency virus (HIV) in an HIV-infected subject undergoing antiretroviral therapy using an adenovirus primer vaccine in combination with an MVA booster vaccine. The methods of priming and boosting an immune response according to embodiments of the invention are effective to induce an immune response against one or multiple clades of HIV.

In one general aspect, a method of inducing an immune response against a human immunodeficiency virus (HIV) in an HIV-infected human subject undergoing antiretroviral therapy (ART) comprises:

-   -   (i) administering to the human subject a primer vaccine         comprising an immunogenically effective amount of one or more         Ad26 vectors encoding one or more mosaic HIV gag, pol and/or env         antigens and a pharmaceutically acceptable carrier; and     -   (ii) administering to the human subject a booster vaccine         comprising an immunogenically effective amount of one or more         MVA vectors encoding one or more mosaic HIV gag, pol and/or env         antigens and a pharmaceutically acceptable carrier.

In certain embodiments, the booster vaccine is first administered at about 12-52 weeks, e.g. about 16-32, e.g. about 22-26, e.g. about 24 weeks, after the primer vaccine is initially administered. One of ordinary skill in the art will be able to vary the exact timing of the priming and boosting vaccines, frequency of administration thereof, dosage thereof, etc., based upon the teachings herein and clinical experience.

Any of the primer and booster vaccine compositions described herein can be used in a method of inducing an immune response against HIV according to the invention. Embodiments of the primer vaccine; booster vaccine; Ad26 vectors; MVA vectors; mosaic HIV gag, pol and/or env antigens encoded by the Ad26 and MVA vectors, etc. that can be used in the methods of the invention are discussed in detail above and in the illustrative examples below.

According to embodiments of the invention, “inducing an immune response” when used with reference to the methods described herein encompasses causing a desired immune response or effect in a subject in need thereof against an infection, such as HIV infection, preferably for therapeutic purposes. “Inducing an immune response” also encompasses providing a therapeutic immunity for treating against a pathogenic agent, i.e., HIV. As used herein, the term “therapeutic immunity” or “therapeutic immune response” means that the HIV infected vaccinated subject is able to control an infection with the pathogenic agent, i.e., HIV, against which the vaccination was done. In one embodiment, “inducing an immune response” refers to causing or improving cellular immunity, e.g., T cell response, against HIV infection. Typically, the administration of the primer and booster vaccine compositions according to embodiments of the invention will have a therapeutic aim to generate an immune response against HIV after HIV infection or development of symptoms characteristic of HIV infection.

The patient population for treatment according to the methods of the invention described herein is HIV-infected human subjects, particularly HIV-infected human subjects undergoing antiretroviral therapy (ART). The terms “HIV infection” and “HIV-infected” as used herein refer to invasion of a human host by HIV. As used herein, “an HIV-infected human subject” refers to a human subject in whom HIV has invaded and subsequently replicated and propagated within the human host, thus causing the human host to be infected with HIV or have an HIV infection or symptoms thereof.

As used herein, “undergoing antiretroviral therapy” refers to a human subject, particularly an HIV-infected human subject, that is being administered, or who has initiated treatment with antiretroviral drugs. According to embodiments of the invention, the antiretroviral therapy (ART) is started prior to the first administration of the primer vaccine, for instance, about 2 to 6 weeks prior, such as about 2, 3, 4, 5, or 6 weeks prior, or 2-24 months prior, such as about 2, 3, 5, 6, 8, 12, 16, 20 or 24 months prior, or longer. In certain embodiments the ART is started about 4 weeks prior to the first administration of the primer vaccine. In a subject undergoing antiretroviral therapy, the antiretroviral therapy is continued during administration of the prime/boost vaccine regimen of the invention.

In certain embodiments, a human subject undergoing antiretroviral therapy is on current stable ART for at least four weeks and has plasma HIV ribonucleic acid (RNA) levels at less than 50 copies/mL for at least 24 weeks to at least 52 weeks, and preferably at least 48 weeks prior to initiation of a prime/boost vaccine regimen according to the invention. However, the human subject can have one or more blips (i.e., instances) of plasma HIV RNA greater than 50 copies/ml to less than 200 copies/ml within this period, such as within the 48 week period prior to the initiation of a prime/boost vaccine regimen, provided that screening immediately prior to initiation of the prime/boost vaccine regimen is less than 50 copies/ml.

In a preferred embodiment, the subject initiated ART during acute HIV infection. The term “acute HIV infection” refers to the initial stage of HIV infection. In general, there are three stages of HIV infection: (1) acute HIV infection, (2) clinical latency, and (3) acquired immunodeficiency syndrome (AIDS). During acute HIV infection, the host typically develops symptoms such as fever, swollen glands, sore throat, rash, muscle and joint aches and pains, headache, etc., as a result of the body's natural response to the HIV infection. During the acute stage of infection, large amounts of the HIV virus are produced in the host, and CD4 levels can decrease rapidly, because the HIV uses CD4 to replicate and then subsequently destroys the CD4. Once the natural immune response of the host brings the level of HIV in the host to a stable level, also known as viral set point, CD4 count begins to increase, but likely not to pre-infection levels. Acute HIV infection is also characterized as Fiebig stages I, II, III, and IV.

Acute HIV infection is typically within two to four weeks after a host is exposed to and infected with HIV and continues for an additional two to four weeks. The acute HIV infection stage lasts until the host creates its own antibodies against HIV, at which point the clinical latency stage begins. During the clinical latency stage, HIV is living or developing in the host without causing any symptoms, or only causing mild symptoms. HIV reproduces at very low levels during the clinical latency stage, although the HIV is still active. The clinical latency stage is sometimes also referred to as ‘chronic HIV infection’ or ‘asymptomatic HIV infection’. In certain embodiments of the invention, the subject initiated ART within 4, preferably 3, more preferably 2 weeks of diagnosis of primary HIV infection.

According to embodiments of the invention, a subject who initiates ART during acute HIV infection begins treatment with antiretroviral drugs at about 2 weeks to about 8 weeks after being exposed to and infected with HIV, such as about 2, 3, 4, 5, 6, 7, or 8 weeks after exposure and infection. Subjects who began ART during acute HIV infection and have plasma HIV RNA levels of less than 50 copies/mol for at least 24 weeks, preferably at least 48 weeks, have low HIV viral reservoirs and therefore have a high chance for maintained viral suppression in the absence of ART, i.e., HIV remission.

A subject undergoing ART can be administered or treated with any antiretroviral drugs known in the art in view of the present disclosure. ART are medications that treat HIV, although the drugs do not kill or cure the virus. However, when taken in combination they can prevent the growth of the virus. When the virus is slowed down, so is HIV disease. Antiretroviral drugs are referred to as ARV. Combination ARV therapy (cART) is referred to as highly active ART (HAART). One of ordinary skill in the art will be able to determine the appropriate antiretroviral treatment, frequency of administration, dosage of the ART, etc. so as to be compatible with simultaneous administration of the Ad26 prime/MVA boost vaccine regimens of the invention. Examples of antiretroviral drugs used for ART include, but are not limited to nucleoside reverse transcriptase inhibitors (NRTIs, non-limiting examples of which include zidovudine, didanosine, stavudine, lamivudine, abacavir, tenofovir, combivir [combination of zidovudine and lamivudine], trizivir [combination of zidovudine, lamivudine and abacavir], emtricitabine, truvada [combination of emtricitabine and tenofovir], and epzicom [combination of abacavir and lamivudine]), non-nucleoside reverse transcriptase inhibitors (NNRTIs, non-limiting examples of which include nevirapine, delavirdine, efavirenz, etravirine, and rilpivirine), protease inhibitors (PIs, non-limiting examples of which include saquinavir, indinavir, ritonavir, nelfinavir, amprenavir, lopinavir/ritonavir, atazanavir, fosamprenavir, tipranavir, darunavir), integrase inhibitors (INSTIs, non-limiting examples including raltegravir, elvitegravir, and dolutegravir), and fusion inhibitors, entry inhibitors and/or chemokine receptor antagonists (FIs, CCRS antagonists; non-limiting examples including enfuvirtide, aplaviroc, maraviroc, vicriviroc, and cnicriviroc).

In a method of inducing an immune response against HIV according to the invention, an HIV-infected human subject undergoing ART is administered a primer vaccine at least once and a booster vaccine at least once. According to embodiments of the invention, the booster vaccine is first administered at about 22-26 weeks, such as 22, 23, 24, 25, or 26 weeks after the primer vaccine is initially administered. In certain embodiments, the booster vaccine is first administered at about 24 weeks after the primer vaccine is initially administered.

In some embodiments, the primer vaccine is re-administered after the primer vaccine is initially administered, and preferably re-administered before the booster vaccine is first administered. For example, the primer vaccine can be re-administered at about 10-14 weeks after the primer vaccine is initially administered, such as about 10, 11, 12, 13, or 14 weeks after the primer vaccine is initially administered, preferably at about 12 weeks after the primer vaccine is initially administered.

In other embodiments, the booster vaccine is re-administered after the booster vaccine is first administered. The booster vaccine can be administered at about 46 to 50 weeks, such as 46, 47, 48, 49, or 50 weeks after the primer vaccine is initially administered. In certain preferred embodiments, the booster vaccine is re-administered at about 48 weeks after the primer vaccine is initially administered.

In particular embodiments of the invention, both the primer vaccine and the booster vaccine are re-administered to the subject. The primer vaccine can be re-administered at about 10-14 weeks, such as for instance about 12 weeks after the primer vaccine is initially administered; and the booster vaccine can be re-administered at about 46 to 50 weeks, such as for instance about 48 weeks after the primer vaccine is initially administered.

Further booster administrations are possible, and embodiments of the disclosed methods also contemplate administration of such additional boosting immunizations with immunogenic compositions containing Ad26 vectors and/or MVA vectors. Any of the Ad26 vectors and MVA vectors described herein can be used in additional boosting immunizations. Preferably, any additional booster immunizations are with immunogenic compositions comprising MVA vectors encoding one or more mosaic HIV gag, pol, and env antigens, such as those comprising the amino acid sequences of SEQ ID NOs: 1-4.

The primer and booster vaccine compositions can be administered by any method known in the art in view of the present disclosure, and administration is typically via intramuscular, intradermal or subcutaneous administration, preferably intramuscular. Intramuscular administration can be achieved by using a needle to inject a suspension of the adenovirus and/or MVA vectors. An alternative is the use of a needleless injection device to administer the composition (using, e.g., Biojector™) or a freeze-dried powder containing the vaccine.

Other modes of administration, such as intravenous, cutaneous, intradermal or nasal are also envisaged as well. For intravenous, cutaneous or subcutaneous injection, the vector will be in the form of a parenterally acceptable aqueous solution which is pyrogen-free and has suitable pH, isotonicity and stability. Those of ordinary skill in the art are well able to prepare suitable solutions using, for example, isotonic vehicles such as Sodium Chloride Injection, Ringer's Injection, and Lactated Ringer's Injection. Preservatives, stabilizers, buffers, antioxidants and/or other additives can be included, as required. A slow-release formulation can also be employed.

In one exemplary regimen, the primer vaccine comprising one or more adenovirus 26 vectors is administered (e.g., intramuscularly) in an amount of about 100 μl to about 2 ml, preferably about 0.5 ml, of saline solution containing concentrations of about 10⁸ to 10¹² virus particles/ml. The initial primer vaccination is followed by a boost as described above. The booster vaccine comprising one more MVA vectors is administered (e.g., intramuscularly) in an amount of about 100 μl to about 2 ml, preferably about 0.5 ml, of saline solution containing concentrations of about 10⁶ to 10⁹ particle forming units/ml. The skilled artisan will appreciate that certain factors may influence the dosage required to effectively treat a subject, including but not limited to the severity of the disease or disorder, previous treatments, the general health and/or age of the subject, and other diseases present.

In preferred embodiments, subjects undergo interruption (also referred to as discontinuation, used interchangeably herein) of ART after completion of the vaccine regimen according to embodiments of the invention. In some embodiments, subjects can undergo antiretroviral analytical treatment interruption (ARV ATI) after completion of vaccine regimen according to embodiments of the invention. “Antiretroviral analytical treatment interruption” and “ARV ATI” as used in the invention refer to discontinuation of treatment with antiretroviral drugs in order to assess viral suppression and viremic control in the absence of continued ART. Typically, subjects can undergo ARV ATI, i.e., ART can be discontinued, when the subject has plasma HIV RNA levels at less than 50 copies/mL for at least about 52 weeks, but a subject can still undergo ARV ATI even if the subject has one or more blips (i.e., instances) of plasma HIV RNA greater than 50 copies/ml to less than 200 copies/ml within this period, provided that the screening immediately prior to ARV ATI shows less than 50 copies/ml of plasma HIV RNA.

According to embodiments of the invention, the ART can be stopped at about 10-14 weeks, such as 10, 11, 12, 13, or 14 weeks after the last booster vaccine is administered. In certain embodiments, the last booster vaccine is administered at about 46-50 weeks after the primer vaccine is initially administered. In these embodiments, the ART can be stopped at about 58 to 62 weeks, such as 58, 59, 60, 61, or 62 weeks after the primer vaccine is initially administered, and preferably about 60 weeks after the primer vaccine is initially administered. In other embodiments, for subjects who are on non-nucleoside reverse transcriptase inhibitor (NNRTI)-based ART, a boosted protease inhibitor can be administered in place of the NNRTI for about 1-2 weeks prior to stopping ART to reduce the risk of developing NNRTI resistance. It is also possible to administer an activator (e.g. a histone deacetylase inhibitor) during the ATI stage to activate any (e.g. latent) HIV reservoir and thereby improve the immune response.

Subjects undergoing ARV ATI can be monitored, e.g., by measuring plasma HIV RNA levels. For example, monitoring after the initiation of ARV ATI can occur up to two times per week during the first six weeks when rebound viremia is most likely to occur. “Rebound viremia” is defined as plasma HIV RNA levels of greater than 1,000 copies/ml after ARV ATI. ART can be re-initiated in subjects with rebound viremia. Preferably, a subject treated according to the methods of the invention will maintain viremic control after ART interruption. As used herein, “maintain viremic control” is defined as at least 24 weeks with plasma HIV RNA of less than 50 copies/mL after ARV ATI. The “maintained viremic control” criterion is still deemed to be met if there are one or more instances of plasma HIV RNA greater than 50 copies/ml to less than 1000 copies/ml, as long as the subject does not have plasma HIV RNA levels above 1000 copies/ml on two consecutive determinations at least one week apart.

Typically (not using the methods of the instant invention) human HIV-infected subjects have a return of viremia after 2-3 weeks following ART interruption. Without wishing to be bound by any theories, it is believed that vaccine therapy using an adenovirus primer vaccine and an MVA booster vaccine according to embodiments of the invention among individuals with fully suppressed HIV will result in a measurable immune response and maintain viremic control after ARV ATI. In some embodiments, subjects can discontinue ART after being treated according to a method of the invention. Discontinuation of ART can be for long periods of time (e.g., at least 24 weeks, preferably longer, e.g. at least about 28, 32, 36, 40, 44, 48, 52 weeks, 16 months, 18, 20, 22, 24 months, or even longer). Such periods of time in which ART is stopped or discontinued are referred to as a “holiday” or “ART holiday” or “treatment holiday”. In other embodiments, vaccine therapy according to the methods of the invention can provide HIV remission, meaning that viral suppression is maintained in the absence of ART. In certain embodiments of the invention, a human subject that received the priming and boosting vaccines of the invention, discontinues ART and maintains viral suppression for at least 24 weeks after discontinuing ART.

EMBODIMENTS

Embodiment 1 is a method of inducing an immune response against a human immunodeficiency virus (HIV) in an HIV-infected human subject undergoing antiretroviral therapy (ART), the method comprising:

-   -   (i) administering to the human subject a primer vaccine         comprising an immunogenically effective amount of one or more         adenovirus 26 (Ad26) vectors encoding one or more mosaic HIV         gag, pol and/or env antigens and a pharmaceutically acceptable         carrier; and     -   (ii) administering to the human subject a booster vaccine         comprising an immunogenically effective amount of one or more         modified vaccinia ankara (MVA) vectors encoding one or more         mosaic HIV gag, pol and/or env antigens and a pharmaceutically         acceptable carrier.

Embodiment 2 is the method according to embodiment 1, wherein the booster vaccine is first administered at about 12-52 weeks after the primer vaccine is initially administered, preferably wherein the booster vaccine is first administered at about 22-26 weeks after the primer vaccine is initially administered.

Embodiment 3 is the method according to embodiment 1 or embodiment 2, wherein the primer vaccine comprises Ad26 vectors encoding one or more mosaic HIV antigens comprising the amino acid sequences selected from the group consisting of SEQ ID NOs: 1, 3 and 4; and the booster vaccine comprises one or more MVA vectors encoding one or more mosaic HIV antigens comprising the amino acid sequences selected from the group consisting of SEQ ID NOs: 1-4.

Embodiment 4 is the method according to embodiment 3, wherein the primer vaccine comprises Ad26 vectors encoding three mosaic HIV antigens having the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 3, and SEQ ID NO: 4; and the booster vaccine comprises MVA vectors encoding four mosaic HIV antigens having the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, and SEQ ID NO: 4.

Embodiment 5 is the method according to embodiment 4, wherein the immunogenically effective amount of the Ad26 vectors encoding mosaic HIV antigens of SEQ ID NOs: 1, 3, and 4 consists of three Ad26 vectors of which a first Ad26 vector encodes mosaic HIV antigen of SEQ ID NO: 1, a second Ad26 vector encodes mosaic HIV antigen of SEQ ID NO: 3, and a third Ad26 vector encodes mosaic HIV antigen of SEQ ID NO: 4.

Embodiment 6 is the method according to any one of embodiments 1 to 5, wherein the primer vaccine and booster vaccine are administered via intramuscular injection.

Embodiment 7 is the method according to embodiment 5, wherein the first, second, and third Ad26 vectors are administered at a total dose of about 5×10¹⁰ viral particles (vp).

Embodiment 8 is the method according to embodiment 7, wherein the total dose of about 5×10¹⁰ vps is administered intramuscularly at a volume of 0.5 ml.

Embodiment 9 is the method according to embodiment 7 or embodiment 8, wherein the first, second, and third Ad26 vectors are at a ratio of about 2:1:1, respectively.

Embodiment 10 is the method according to any one of embodiments 3-5, wherein the immunogenically effective amount of the MVA vectors encoding mosaic HIV antigens of SEQ ID NOs: 1, 2, 3, and 4 consists of two MVA vectors of which a first MVA vector encodes mosaic HIV antigens of SEQ ID NOs: 1 and 3, and a second MVA vector encodes mosaic HIV antigens of SEQ ID NOs: 2 and 4.

Embodiment 11 is the method according to embodiment 10, wherein the first and second MVA vectors are administered at a total dose of about 1×10⁸ plaque forming units (pfus).

Embodiment 12 is the method according to embodiment 11, wherein the total dose of about 1×10⁸ pfus is administered intramuscularly at a volume of 0.5 ml.

Embodiment 13 is the method according to embodiment 11 or embodiment 12, wherein the first and second MVA vectors are at a ratio of about 1:1.

Embodiment 14 is the method according to any one of claims 1 to 13, further comprising re-administering the primer vaccine at about 10-14 weeks after the primer vaccine is initially administered; and re-administering the booster vaccine at about 46 to 50 weeks after the primer vaccine is initially administered.

Embodiment 15 is the method according to embodiment 14, wherein the primer vaccine is re-administered at about 12 weeks after the primer vaccine is initially administered; the booster vaccine is first administered at about 24 weeks after the primer vaccine is initially administered; and the booster vaccine is re-administered at about 48 weeks after the primer vaccine is initially administered.

Embodiment 16 is the method according to any one of embodiments 1 to 15, wherein the human subject initiated ART during acute HIV infection.

Embodiment 17 is the method according to any one of embodiments 1 to 16, wherein a further booster vaccine is administered, and the further booster vaccine is a composition comprising an immunogenically effective amount of one or more Ad26 vectors encoding one or more mosaic HIV gag, pol and/or env antigens and a pharmaceutically acceptable carrier; or a composition comprising an immunogenically effective amount of one or more MVA vectors encoding one or more mosaic HIV gag, pol, and/or env antigens and a pharmaceutically acceptable carrier.

Embodiment 18 is the method according to embodiment 17, wherein the further booster vaccine is a composition comprising an immunogenically effective amount of one or more MVA vectors encoding one or more mosaic HIV gag, pol, and/or env antigens and a pharmaceutically acceptable carrier.

Embodiment 19 is the method according to embodiment 18, wherein the MVA vectors encode four mosaic HIV antigens having the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, and SEQ ID NO: 4; preferably wherein the immunogenically effective amount of the MVA vectors encoding mosaic HIV antigens of SEQ ID NOs: 1, 2, 3, and 4 consists of two MVA vectors of which a first MVA vector encodes mosaic HIV antigens of SEQ ID NOs: 1 and 3, and a second MVA vector encodes mosaic HIV antigens of SEQ ID NOs: 2 and 4.

Embodiment 20 is the method according to any one of embodiments 1 to 19, wherein the subject is on current stable ART at least four weeks prior to the initial administration of the primer vaccine.

Embodiment 21 is the method according to any one of embodiments 1 to 20, wherein the subject has sustained viremic control defined as plasma HIV RNA of less than 50 copies per ml for at least 48 weeks prior to the initial administration of the primer vaccine, optionally with one or more blips of plasma HIV RNA greater than 50 copies/ml to less than 200 copies/ml, provided that screening immediately prior to the initial administration of the primer vaccine is less than 50 copies/ml.

Embodiment 22 is the method according to any one of embodiments 1-21, wherein the ART is discontinued at about 10-14 weeks after the last booster vaccine is administered.

Embodiment 23 is the method according to embodiment 22, wherein the ART is discontinued at about 12 weeks after the last booster vaccine is administered.

Embodiment 24 is the method according to embodiment 22 or embodiment 23, wherein the subject has sustained viremic control after discontinuing ART.

Embodiment 25 is a method of inducing an immune response against a human immunodeficiency virus (HIV) in an HIV-infected human subject undergoing antiretroviral therapy (ART), the method comprising:

-   -   (i) administering to the human subject a primer vaccine         comprising an immunogenically effective amount of one or more         adenovirus 26 (Ad26) vectors encoding one or more mosaic HIV         antigens comprising the amino acid sequences selected from the         group consisting of SEQ ID NOs: 1, 3, and 4 and a         pharmaceutically acceptable carrier; and     -   (ii) administering to the human subject a booster vaccine         comprising an immunogenically effective amount of one or more         MVA vectors encoding one or more mosaic HIV antigens comprising         the amino acid sequences selected from the group consisting of         SEQ ID NOs: 1-4 and a pharmaceutically acceptable carrier,

wherein the primer vaccine is re-administered at about 10-14 weeks after the primer vaccine is initially administered; the booster vaccine is first administered at about 22-26 weeks after the primer vaccine is initially administered; and the booster vaccine is re-administered at about 46-50 weeks after the primer vaccine is initially administered; and

wherein the human subject initiated ART during acute HIV infection.

Embodiment 26 is the method according to embodiment 25, wherein the immunogenically effective amount of the Ad26 vectors encoding one or more mosaic HIV antigens of SEQ ID NOs: 1, 3, and 4 consists of three Ad26 vectors of which a first Ad26 vector encodes mosaic HIV antigen of SEQ ID NO: 1, a second Ad26 vector encodes mosaic HIV antigen of SEQ ID NO: 3, and a third Ad26 vector encodes mosaic HIV antigen of SEQ ID NO: 4; and wherein the immunogenically effective amount of the MVA vectors encoding one or more mosaic HIV antigens of SEQ ID NOs: 1-4 consists of two MVA vectors of which a first MVA vector encodes mosaic HIV antigens of SEQ ID NOs: 1 and 3, and a second MVA vector encodes mosaic HIV antigens of SEQ ID NOs: 2 and 4.

Embodiment 27 is the method according to embodiment 26, wherein the first, second, and third Ad26 vectors are administered at a total dose of about 5×10¹⁰ vp; and the first and second MVA vectors are administered at a total dose of about 1×10⁸ pfu.

Embodiment 28 is the method according to embodiment 26 or embodiment 27, wherein the first, second, and third Ad26 vectors are at a ratio of about 2:1:1, respectively; and the first and second MVA vectors are at a ratio of about 1:1, respectively.

Embodiment 29 is the method according to any one of embodiments 25-28, wherein the primer vaccine is re-administered at about 12 weeks after the primer vaccine is initially administered, the booster vaccine is first administered at about 24 weeks after the primer vaccine is initially administered, and the booster vaccine is re-administered at about 48 weeks after the primer vaccine is initially administered.

Embodiment 30 is the method according to any one of embodiments 25-29, wherein a further booster vaccine is administered, and the further booster vaccine is a composition comprising an immunogenically effective amount of one or more MVA vectors encoding one or more mosaic HIV antigens comprising the amino acid sequences selected from the group consisting of SEQ ID NOs: 1-4 and a pharmaceutically acceptable carrier, preferably encoding four mosaic HIV antigens having the amino acid sequences of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, and SEQ ID NO: 4.

Embodiment 31 is the method according to any one of embodiments 25-30, wherein the primer vaccine and booster vaccine are administered intramuscularly.

Embodiment 32 is the method according to any one of embodiments 25-31, wherein the subject is on current stable ART at least four weeks prior to the initial administration of the primer vaccine.

Embodiment 33 is the method according to any one of embodiments 25-32, wherein the subject has sustained viremic control defined as plasma HIV RNA of less than 50 copies per ml for at least 48 weeks prior to the initial administration of the primer vaccine, optionally with one or more blips of plasma HIV RNA greater than 50 copies/ml to less than 200 copies/ml, provided that screening immediately prior to the initial administration of the primer vaccine is less than 50 copies/ml.

Embodiment 34 is the method according to any one of embodiments 25-33, wherein the ART is discontinued at about 10-14 weeks after the last booster vaccine is administered.

Embodiment 35 is the method according to embodiment 34, wherein the ART is discontinued at about 12 weeks after the last booster vaccine is administered.

Embodiment 36 is the method according to embodiment 34 or 35, wherein the subject has sustained viremic control after discontinuing ART.

Embodiment 37 is a method according to any one of embodiments 1-36, wherein administration of the primer vaccine and booster vaccine induces an immune response against multiple clades of HIV in the subject.

Embodiment 38 is a method according to any one of embodiments 1-37, wherein a human subject to which the primer vaccine and the booster vaccine has been administered, discontinues ART and maintains viral suppression for at least 24 weeks after discontinuing ART.

The following examples of the invention are to further illustrate the nature of the invention. It should be understood that the following examples do not limit the invention and the scope of the invention is to be determined by the appended claims.

EXAMPLES Example 1: Study of HIV Vaccine Regimens in HIV-Infected Humans Undergoing Antiretroviral Therapy (ART)

Clinical studies in humans are conducted to investigate the effect of Ad26 vector priming immunizations and MVA vector boosting immunizations in HIV-infected human adults after antiretroviral analytical treatment interruption (ARV ATI).

Objectives

The primary objectives of the study include: (1) determining the safety and tolerability of an Ad26 primer/MVA boost vaccine regimen versus placebo in subjects on suppressive ART that was initiated during acute HIV infection; and (2) measuring the frequency and duration of sustained viremic control after receiving Ad26 prime/MVA boost or placebo, defined as greater than 24 weeks with plasma HIV RNA of less than 50 copies/ml after antiretroviral analytical treatment interruption (ARV ATI). The secondary objectives of the study include: (1) determining the immunogenicity of Ad26 prime/MVA boost vaccine regimen in subjects on suppressive ART that was initiated during acute HIV infection; (2) characterizing biomarkers of HIV reservoir at baseline, after vaccine therapy prior to ARV ATI (weeks 48-60 of the study), and after ARV ATI (weeks 60-96 of the study); (3) comparing the duration of viremic control (plasma HIV RNA less than 50 copies/ml) between vaccine and placebo recipients who failed to achieve sustained viremic control at week 24 after ARV ATI; and (4) describing the frequency, magnitude, specificity and functional capacity of humoral and cellular immune responses to vaccines.

Vaccination and Experimental Design

A single-center, randomized, parallel-group, placebo-controlled, double-blind combined Phase 1/2a clinical study in HIV-infected adults aged 18 to 50 years is performed. A target of 36 human subjects are participating in this study. The subjects in the study started on antiretroviral therapy (ART) during acute HIV infection, and are on a current stable ART for at least four weeks prior to initiation of vaccine/placebo, and have achieved absence of viremia (plasma HIV RNA of less than 50 copies/ml) for at least 48 weeks prior to initiation of vaccine/placebo. The subjects are divided into two groups: the test group (24 subjects) and the control group (12 subjects). The subjects in the test group receive the study vaccine, and the subjects in control group receive placebo.

The study continues for 96 weeks and will be carried out in two stages, including a vaccination period of 48 weeks (stage 1), a 12 week period between the final vaccination and antiretroviral analytical treatment interruption (ARV ATI) (stage 1), and a follow-up period of 36 weeks in which all antiretroviral drugs are discontinued, i.e., ARV ATI (stage 2).

Dosage and Administration

Subjects receive four doses of study vaccine: adenovirus 26 vectors encoding mosaic HIV antigens (Ad26_(mos)) or placebo is administered at weeks 0 and 12; and MVA vectors encoding mosaic HIV antigens (MVA_(mos)) or placebo is administered at Weeks 24 and 48. Study vaccines (Ad26_(mos) and MVA_(mos)) and placebo with the administered doses are as follows:

-   -   (i) Ad26_(mos) is composed of the following three vaccine         products supplied in the same vial and administered in a 2:1:1         ratio: Ad26.Mos1Env, Ad26.Mos1Gag-Pol, and Ad26.Mos2Gag-Pol         expressing HIV mosaic Env1 (SEQ ID NO: 1), mosaic GagPol1 (SEQ         ID: NO 3), and mosaic GagPol2 (SEQ ID NO: 4) genes,         respectively; total dose is about 5×10¹⁰ viral particles (vp)         per 0.5 ml injection;     -   (ii) MVA_(mos) is composed of the following two vaccine products         supplied in separate vials and administered in a 1:1 ratio:         MVA-Mosaic1 (MVA virus expressing Mosaic1 HIV-1 Gag, Pol, and         Env proteins having SEQ ID NOs: 1 and 3) and MVA-Mosaic2 (MVA         virus expressing Mosaic2 HIV-1 Gag, Pol, and Env proteins having         SEQ ID NOs: 2 and 4); total dose is about 1×10⁸ plaque forming         units (pfu) per 0.5 ml injection; and     -   (iii) Placebo is 0.9% sodium chloride (0.5 ml injection).

Subjects receive the study vaccines or placebo according to the schedule in Table 1 below in four doses administered by intramuscular injection. Subjects in both the test and control groups receive standard ART for HIV treatment during the first 60 weeks of the trial prior to ARV ATI. Blood and genital secretions are taken at specific clinical visits to assess immune responses (cellular and humoral immune responses) and viremic control throughout the study.

TABLE 1 Schedule for administration of study vaccines Group N Week 0 Week 12 Week 24 Week 48 Test 24 Ad26_(mos) Ad26_(mos) MVA_(mos) MVA_(mos) Control 12 Placebo Placebo Placebo Placebo

At week 60, all treatment with antiretroviral drugs is stopped to initiate ARV ATI (stage 2). Subjects on non-nucleoside reserve transcriptase inhibitor (NNRTI)-based antiretroviral drugs are administered a boosted protease inhibitor (lopinavir/ritonavir; atazanavir/ritonavir; or darunavir/ritonavir) instead of NNRTI from weeks 58 to 60 to reduce the risk of NNRTI resistance. Virological monitoring after ATI is performed up to two times per week during the first 6 weeks when rebound viremia is most likely to occur. ARV ATI is initiated in subjects who have plasma HIV RNA of less than 50 copies/ml for the previous 52 weeks. Subjects who have blips of more than 50 copies/ml but less than 200 copies/ml of plasma HIV RNA start ARV ATI provided that the most recent result is less than 50 copies/ml. During ARV ATI, the duration of viral control is determined and follow-up for subjects who resume therapy, i.e., fail to maintain viremic control, is performed.

ART is re-initiated in the subjects at the end of the trial at week 96, and if the subjects fail to maintain viremic control during ARV ATI (weeks 60 to 96). ART is re-initiated in subjects during ARV ATI with rebound viremia who have plasma HIV RNA levels above 1000 copies/ml on two consecutive determinations at least one week apart. The main endpoint for efficacy is the proportion of subjects with plasma HIV RNA of less than 50 copies/ml at 24 weeks after the initiation of ARV ATI.

It is understood that the examples and embodiments described herein are for illustrative purposes only, and that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the invention as defined by the appended claims.

SEQUENCE LISTING SEQ ID NO: 1 (Mos1.Env) 685 aa: MRVTGIRKNYQHLWRWGTMLLGILMICSAAGKLWVTVYYGVPVWKEATTTLFCASDAKAYDTEVHNVWAT HACVPTDPNPQEVVLENVTENFNMWKNNMVEQMHEDIISLWDQSLKPCVKLTPLCVTLNCTDDVRNVTNN ATNTNSSWGEPMEKGEIKNCSFNITTSIRNKVQKQYALFYKLDVVPIDNDSNNTNYRLISCNTSVITQAC PKVSFEPIPIHYCAPAGFAILKCNDKKFNGTGPCTNVSTVQCTHGIRPVVSTQLLLNGSLAEEEVVIRSE NFTNNAKTIMVQLNVSVEINCTRPNNNTRKSIHIGPGRAFYTAGDIIGDIRQAHCNISRANWNNTLRQIV EKLGKQFGNNKTIVFNHSSGGDPEIVMHSFNCGGEFFYCNSTKLFNSTWTWNNSTWNNTKRSNDTEEHIT LPCRIKQIINMWQEVGKAMYAPPIRGQIRCSSNITGLLLTRDGGNDTSGTEIFRPGGGDMRDNWRSELYK YKVVKIEPLGVAPTKAKRRVVQSEKSAVGIGAVFLGFLGAAGSTMGAASMTLTVQARLLLSGIVQQQNNL LRAIEAQQHLLQLTVWGIKQLQARVLAVERYLKDQQLLGIWGCSGKLICTTTVPWNASWSNKSLDKIWNN MTWMEWEREINNYTSLIYTLIEESQNQQEKNEQELLELDKWASLWNWFDISNWLW SEQ ID NO: 2 (Mos2.Env) 684 aa: MRVRGIQRNWPQWWIWGILGFWMIIICRVMGNLWVTVYYGVPVWKEAKTTLFCASDAKAYEKEVHNVWAT HACVPTDPNPQEMVLENVTENFNMWKNDMVDQMHEDIIRLWDQSLKPCVKLTPLCVTLECRNVRNVSSNG TYNIIHNETYKEMKNCSFNATTVVEDRKQKVHALFYRLDIVPLDENNSSEKSSENSSEYYRLINCNTSAI TQACPKVSFDPIPIHYCAPAGYAILKCNNKTFNGTGPCNNVSTVQCTHGIKPVVSTQLLLNGSLAEEEII IRSENLTNNAKTIIVHLNETVNITCTRPNNNTRKSIRIGPGQTFYATGDIIGDIRQAHCNLSRDGWNKTL QGVKKKLAEHFPNKTINFTSSSGGDLEITTHSFNCRGEFFYCNTSGLFNGTYMPNGTNSNSSSNITLPCR IKQIINMWQEVGRAMYAPPIAGNITCRSNITGLLLTRDGGSNNGVPNDTETFRPGGGDMRNNWRSELYKY KVVEVKPLGVAPTEAKRRVVESEKSAVGIGAVFLGILGAAGSTMGAASITLTVQARQLLSGIVQQQSNLL RAIEAQQHMLQLTVWGIKQLQTRVLAIERYLQDQQLLGLWGCSGKLICTTAVPWNTSWSNKSQTDIWDNM TWMQWDKEIGHYTGEIYRLLEESQNQQEKNEKDLLALDSWKNLWNWFDITNWLW SEQ ID NO: 3 (Mos1.Gag-Pol) 1350 aa: MGARASVLSGGELDRWEKIRLRPGGKKKYRLKHIVWASRELERFAVNPGLLETSEGCRQILGQLQPSLQT GSEELRSLYNTVATLYCVHQRIEIKDTKEALEKIEEEQNKSKKKAQQAAADTGNSSQVSQNYPIVQNIQG QMVHQAISPRTLNAWVKVVEEKAFSPEVIPMFSALSEGATPQDLNTMLNTVGGHQAAMQMLKETINEEAA EWDRVHPVHAGPIAPGQMREPRGSDIAGTTSTLQEQIGWMTNNPPIPVGEIYKRWIILGLNKIVRMYSPA SILDIRQGPKEPFRDYVDRFYKTLRAEQASQDVKNWMTETLLVQNANPDCKTILKALGPAATLEEMMTAC QGVGGPGHKARVLAEAMSQVTNSATIMMQRGNFRNQRKTVKCFNCGKEGHIAKNCRAPRKKGCWKCGKEG HQMKDCTERQANFLGKIWPSNKGRPGNFLQNRPEPTAPPEESFRFGEETTTPSQKQEPIDKEMYPLASLK SLFGNDPSSQMAPISPIETVPVKLKPGMDGPRVKQWPLTEEKIKALTAICEEMEKEGKITKIGPENPYNT PVFAIKKKDSTKWRKLVDFRELNKRTQDFWEVQLGIPHPAGLKKKKSVTVLAVGDAYFSVPLDEGFRKYT AFTIPSTNNETPGIRYQYNVLPQGWKGSPAIFQCSMTRILEPFRAKNPEIVIYQYMAALYVGSDLEIGQH RAKIEELREHLLKWGFTTPDKKHQKEPPFLWNGYELHPDKWTVQPIQLPEKDSWTVNDIQKLVGKLNWAS QIYPGIKVRQLCKLLRGAKALTDIVPLTEEAELELAENREILKEPVHGVYYDPSKDLIAEIQKQGHDQWT YQIYQEPFKNLKTGKYAKMRTAHTNDVKQLTEAVQKIAMESIVIWGKTPKFRLPIQKETWETWWTDYWQA TWIPEWEFVNTPPLVKLWYQLEKDPIAGVETFYVAGAANRETKLGKAGYVTDRGRQKIVSLTETTNQKTA LQAIYLALQDSGSEVNIVTASQYALGIIQAQPDKSESELVNQIIEQLIKKERVYLSWVPAHKGIGGNEQV DKLVSSGIRKVLFLDGIDKAQEEHEKYHSNWRAMASDFNLPPVVAKEIVASCDQCQLKGEAMHGQVDCSP GIWQLACTHLEGKIILVAVHVASGYIEAEVIPAETGQETAYFILKLAGRWPVKVIHTANGSNFTSAAVKA ACWWAGIQQEFGIPYNPQSQGVVASMNKELKKIIGQVRDQAEHLKTAVQMAVFIHNFKRKGGIGGYSAGE RIIDIIATDIQTKELQKQIIKIQNFRVYYRDSRDPIWKGPAKLLWKGEGAVVIQDNSDIKVVPRRKVKII KDYGKQMAGADCVAGRQDED SEQ ID NO: 4 (Mos2.Gag-Pol) 1341 aa: MGARASILRGGKLDKWEKIRLRPGGKKHYMLKHLVWASRELERFALNPGLLETSEGCKQIIKQLQPALQT GTEELRSLFNTVATLYCVHAEIEVRDTKEALDKIEEEQNKSQQKTQQAKEADGKVSQNYPIVQNLQGQMV HQPISPRTLNAWVKVIEEKAFSPEVIPMFTALSEGATPQDLNTMLNTVGGHQAAMQMLKDTINEEAAEWD RLHPVHAGPVAPGQMREPRGSDIAGTTSNLQEQIAWMTSNPPIPVGDIYKRWIILGLNKIVRMYSPTSIL DIKQGPKEPFRDYVDRFFKTLRAEQATQDVKNWMTDTLLVQNANPDCKTILRALGPGATLEEMMTACQGV GGPSHKARVLAEAMSQTNSTILMQRSNFKGSKRIVKCFNCGKEGHIARNCRAPRKKGCWKCGKEGHQMKD CTERQANFLGKIWPSHKGRPGNFLQSRPEPTAPPAESFRFEETTPAPKQEPKDREPLTSLRSLFGSDPLS QMAPISPIETVPVKLKPGMDGPKVKQWPLTEEKIKAVLEICTEMEKEGKISKIGPENPYNTPIFAIKKKD STKWRKLVDFRELNKRTQDFWEVQLGIPHPAGLKKKKSVTVLAVGDAYFSVPLDEDFRKYTAFTIPSINN ETPGIRYQYNVLPQGWKGSPAIFQSSMTKILEPFRKQNPDIVIYQYMAALYVGSDLEIGQHRTKIEELRQ HLLRWGFTTPDKKHQKEPPFLWMGYELHPDKWTVQPIVLPEKDSWTVNDIQKLVGKLNWASQIYAGIKVK QLCKLLRGTKALTEVVPLTEEAELELAENREILKEPVHGVYYDPSKDLIAEIQKQGQGQWTYQIYQEPFK NLKTGKYARMRGAHTNDVKQLTEAVQKIATESIVIWGKTPKFKLPIQKETWEAWWTEYWQATWIPEWEFV NTPPLVKLWYQLEKEPIVGAETFYVAGAANRETKLGKAGYVTDRGRQKVVSLTDTTNQKTALQAIHLALQ DSGLEVNIVTASQYALGIIQAQPDKSESELVSQIIEQLIKKEKVYLAWVPAHKGIGGNEQVDKLVSRGIR KVLFLDGIDKAQEEHEKYHSNWRAMASEFNLPPIVAKEIVASCDKCQLKGEAIHGQVDCSPGIWQLACTH LEGKVILVAVHVASGYIEAEVIPAETGQETAYFLLKLAGRWPVKTIHTANGSNFTSATVKAACWWAGIKQ EFGIPYNPQSQGVVASINKELKKIIGQVRDQAEGLKTAVQMAVFIHNFKRKGGIGEYSAGERIVDIIASD IQTKELQKQITKIQNFRVYYRDSRDPLWKGPAKLLWKGEGAVVIQDNSDIKVVPRRKAKIIRDYGKQMAG DDCVASRQDED SEQ ID NO: 5 (Mos1.Env DNA) ATGCGGGTGACCGGCATCCGGAAGAACTACCAGCACCTGTGGCGGTGGGGCACCATGCTGCTGGGCATCC TGATGATTTGCTCTGCCGCCGGAAAGCTGTGGGTGACCGTGTACTACGGCGTGCCCGTGTGGAAAGAGGC CACCACCACCCTGTTCTGCGCCAGCGACGCCAAGGCCTACGACACCGAGGTGCACAACGTGTGGGCCACC CACGCCTGCGTGCCCACCGACCCCAACCCCCAGGAAGTGGTCCTGGAAAACGTGACCGAGAACTTCAACA TGTGGAAGAACAACATGGTGGAGCAGATGCACGAGGACATCATCAGCCTGTGGGACCAGAGCCTGAAGCC CTGCGTGAAGCTGACCCCCCTGTGCGTGACCCTGAACTGCACCGACGACGTGCGGAACGTGACCAACAAC GCCACCAACACCAACAGCAGCTGGGGCGAGCCTATGGAAAAGGGCGAGATCAAGAACTGCAGCTTCAACA TCACCACCTCCATCCGGAACAAGGTGCAGAAGCAGTACGCCCTGTTCTACAAGCTGGACGTGGTGCCCAT CGACAACGACAGCAACAACACCAACTACCGGCTGATCAGCTGCAACACCAGCGTGATCACCCAGGCCTGC CCCAAGGTGTCCTTCGAGCCCATCCCCATCCACTACTGCGCCCCTGCCGGCTTCGCCATCCTGAAGTGCA ACGACAAGAAGTTCAACGGCACCGGCCCCTGCACCAACGTGAGCACCGTGCAGTGCACCCACGGCATCCG GCCCGTGGTGTCCACCCAGCTGCTGCTGAACGGCAGCCTGGCCGAGGAAGAGGTGGTGATCAGAAGCGAG AATTTCACCAACAATGCCAAGACCATCATGGTGCAGCTGAACGTGAGCGTGGAGATCAACTGCACCCGGC CCAACAACAACACCCGGAAGAGCATCCACATCGGCCCTGGCAGGGCCTTCTACACAGCCGGCGACATCAT CGGCGACATCCGGCAGGCCCACTGCAACATCAGCCGGGCCAACTGGAACAACACCCTGCGGCAGATCGTG GAGAAGCTGGGCAAGCAGTTCGGCAACAACAAGACCATCGTGTTCAACCACAGCAGCGGCGGAGACCCCG AGATCGTGATGCACAGCTTCAACTGTGGCGGCGAGTTCTTCTACTGCAACAGCACCAAGCTGTTCAACAG CACCTGGACCTGGAACAACTCCACCTGGAATAACACCAAGCGGAGCAACGACACCGAAGAGCACATCACC CTGCCCTGCCGGATCAAGCAGATTATCAATATGTGGCAGGAGGTCGGCAAGGCCATGTACGCCCCTCCCA TCCGGGGCCAGATCCGGTGCAGCAGCAACATCACCGGCCTGCTGCTGACCCGGGACGGCGGCAACGATAC CAGCGGCACCGAGATCTTCCGGCCTGGCGGCGGAGATATGCGGGACAACTGGCGGAGCGAGCTGTACAAG TACAAGGTGGTGAAGATCGAGCCCCTGGGCGTGGCTCCCACCAAGGCCAAGCGGCGGGTGGTGCAGAGCG AGAAGAGCGCCGTGGGCATCGGCGCCGTGTTTCTGGGCTTCCTGGGAGCCGCCGGAAGCACCATGGGAGC CGCCAGCATGACCCTGACCGTGCAGGCCCGGCTGCTGCTGTCCGGCATCGTGCAGCAGCAGAACAACCTG CTCCGGGCCATCGAGGCCCAGCAGCACCTGCTGCAGCTGACCGTGTGGGGCATCAAGCAGCTGCAGGCCA GGGTGCTGGCCGTGGAGAGATACCTGAAGGATCAGCAGCTCCTGGGGATCTGGGGCTGCAGCGGCAAGCT GATCTGCACCACCACCGTGCCCTGGAACGCCAGCTGGTCCAACAAGAGCCTGGACAAGATCTGGAACAAT ATGACCTGGATGGAATGGGAGCGCGAGATCAACAATTACACCAGCCTGATCTACACCCTGATCGAGGAAA GCCAGAACCAGCAGGAAAAGAACGAGCAGGAACTGCTGGAACTGGACAAGTGGGCCAGCCTGTGGAACTG GTTCGACATCAGCAACTGGCTGTGG SEQ ID NO: 6 (Mos2.Env DNA) ATGAGAGTGCGGGGCATCCAGCGGAACTGGCCCCAGTGGTGGATCTGGGGCATCCTGGGCTTTTGGATGA TCATCATCTGCCGGGTGATGGGCAACCTGTGGGTGACCGTGTACTACGGCGTGCCCGTGTGGAAAGAGGC CAAGACCACCCTGTTCTGCGCCAGCGACGCCAAGGCCTACGAGAAAGAGGTGCACAACGTGTGGGCCACC CACGCCTGCGTGCCCACCGACCCCAACCCCCAGGAAATGGTCCTGGAAAACGTGACCGAGAACTTCAACA TGTGGAAGAACGACATGGTGGACCAGATGCACGAGGACATCATCCGGCTGTGGGACCAGAGCCTGAAGCC CTGCGTGAAGCTGACCCCCCTGTGCGTGACCCTGGAATGCCGGAACGTGAGAAACGTGAGCAGCAACGGC ACCTACAACATCATCCACAACGAGACCTACAAAGAGATGAAGAACTGCAGCTTCAACGCCACCACCGTGG TGGAGGACCGGAAGCAGAAGGTGCACGCCCTGTTCTACCGGCTGGACATCGTGCCCCTGGACGAGAACAA CAGCAGCGAGAAGTCCAGCGAGAACAGCTCCGAGTACTACCGGCTGATCAACTGCAACACCAGCGCCATC ACCCAGGCCTGCCCCAAGGTGTCCTTCGACCCCATCCCCATCCACTACTGCGCCCCTGCCGGCTACGCCA TCCTGAAGTGCAACAACAAGACCTTCAACGGCACCGGCCCCTGCAACAACGTGAGCACCGTGCAGTGCAC CCACGGCATCAAGCCCGTGGTGTCCACCCAGCTGCTGCTGAACGGCAGCCTGGCCGAGGAAGAGATCATC ATCCGGTCCGAGAACCTGACCAACAACGCCAAGACCATCATCGTGCACCTGAATGAGACCGTGAACATCA CCTGCACCCGGCCCAACAACAACACCCGGAAGAGCATCCGGATCGGCCCTGGCCAGACCTTTTACGCCAC CGGCGACATCATCGGCGACATCCGGCAGGCCCACTGCAACCTGAGCCGGGACGGCTGGAACAAGACCCTG CAGGGCGTGAAGAAGAAGCTGGCCGAGCACTTCCCCAATAAGACCATCAACTTCACCAGCAGCAGCGGCG GAGACCTGGAAATCACCACCCACAGCTTCAACTGCAGGGGCGAGTTCTTCTACTGCAATACCTCCGGCCT GTTCAATGGCACCTACATGCCCAACGGCACCAACAGCAACAGCAGCAGCAACATCACCCTGCCCTGCCGG ATCAAGCAGATCATCAATATGTGGCAGGAGGTCGGCAGGGCCATGTACGCCCCTCCCATCGCCGGCAATA TCACCTGCCGGTCCAACATCACCGGCCTGCTGCTGACCAGGGACGGCGGCAGCAACAACGGCGTGCCTAA CGACACCGAGACCTTCCGGCCTGGCGGCGGAGATATGCGGAACAACTGGCGGAGCGAGCTGTACAAGTAC AAGGTGGTGGAGGTGAAGCCCCTGGGCGTGGCTCCTACCGAGGCCAAGCGGCGGGTGGTGGAGAGCGAGA AGAGCGCCGTGGGCATCGGCGCCGTGTTTCTGGGCATTCTGGGAGCCGCCGGAAGCACCATGGGAGCCGC CAGCATCACCCTGACCGTGCAGGCCCGGCAGCTGCTGTCCGGCATCGTGCAGCAGCAGAGCAACCTGCTG AGAGCCATCGAGGCCCAGCAGCACATGCTGCAGCTGACCGTGTGGGGCATCAAGCAGCTGCAGACCCGGG TGCTGGCCATCGAGAGATACCTGCAGGATCAGCAGCTCCTGGGCCTGTGGGGCTGCAGCGGCAAGCTGAT CTGCACCACCGCCGTGCCCTGGAACACCAGCTGGTCCAACAAGAGCCAGACCGACATCTGGGACAACATG ACCTGGATGCAGTGGGACAAAGAGATCGGCAACTACACCGGCGAGATCTACAGGCTGCTGGAAGAGAGCC AGAACCAGCAGGAAAAGAACGAGAAGGACCTGCTGGCCCTGGACAGCTGGAAGAACCTGTGGAACTGGTT CGACATCACCAACTGGCTGTGG SEQ ID NO: 7 (Mos1.Gag-Pol DNA) ATGGGAGCCAGAGCCAGCGTGCTGTCCGGAGGGGAGCTGGACCGCTGGGAGAAGATCAGGCTGAGGCCTG GAGGGAAGAAGAAGTACAGGCTGAAGCACATCGTGTGGGCCAGCAGAGAGCTGGAACGGTTTGCCGTGAA CCCTGGCCTGCTGGAAACCAGCGAGGGCTGTAGGCAGATTCTGGGACAGCTGCAGCCCAGCCTGCAGACA GGCAGCGAGGAACTGCGGAGCCTGTACAACACCGTGGCCACCCTGTACTGCGTGCACCAGCGGATCGAGA TCAAGGACACCAAAGAAGCCCTGGAAAAGATCGAGGAAGAGCAGAACAAGAGCAAGAAGAAAGCCCAGCA GGCTGCCGCTGACACAGGCAACAGCAGCCAGGTGTCCCAGAACTACCCCATCGTGCAGAACATCCAGGGA CAGATGGTGCACCAGGCCATCAGCCCTCGGACCCTGAACGCCTGGGTGAAGGTGGTGGAGGAAAAGGCCT TCAGCCCTGAGGTGATCCCCATGTTCTCTGCCCTGAGCGAGGGAGCCACACCCCAGGACCTGAACACCAT GCTGAACACCGTGGGAGGGCACCAGGCTGCCATGCAGATGCTGAAAGAGACAATCAACGAGGAAGCTGCC GAGTGGGACAGGGTCCACCCAGTGCACGCTGGACCTATCGCTCCTGGCCAGATGAGAGAGCCCAGAGGCA GCGATATTGCTGGCACCACCTCCACACTGCAGGAACAGATCGGCTGGATGACCAACAACCCTCCCATCCC TGTGGGAGAGATCTACAAGCGGTGGATCATTCTGGGACTGAACAAGATCGTGCGGATGTACAGCCCTGTG AGCATCCTGGACATCAGGCAGGGACCCAAAGAGCCCTTCAGGGACTACGTGGACCGGTTCTACAAGACCC TGAGAGCCGAGCAGGCCAGCCAGGACGTGAAGAACTGGATGACCGAGACACTGCTGGTGCAGAACGCCAA CCCTGACTGCAAGACCATCCTGAAAGCCCTGGGACCTGCTGCCACCCTGGAAGAGATGATGACAGCCTGC CAGGGAGTGGGAGGACCTGGCCACAAGGCCAGGGTGCTGGCCGAGGCCATGAGCCAGGTGACCAACTCTG CCACCATCATGATGCAGAGAGGCAACTTCCGGAACCAGAGAAAGACCGTGAAGTGCTTCAACTGTGGCAA AGAGGGACACATTGCCAAGAACTGCAGGGCTCCCAGGAAGAAAGGCTGCTGGAAGTGCGGAAAAGAAGGC CACCAGATGAAGGACTGCACCGAGAGGCAGGCCAACTTCCTGGGCAAGATCTGGCCTAGCAACAAGGGCA GGCCTGGCAACTTCCTGCAGAACAGACCCGAGCCCACCGCTCCTCCCGAGGAAAGCTTCCGGTTTGGCGA GGAAACCACCACCCCTAGCCAGAAGCAGGAACCCATCGACAAAGAGATGTACCCTCTGGCCAGCCTGAAG AGCCTGTTCGGCAACGACCCCAGCAGCCAGATGGCTCCCATCAGCCCAATCGAGACAGTGCCTGTGAAGC TGAAGCCTGGCATGGACGGACCCAGGGTGAAGCAGTGGCCTCTGACCGAGGAAAAGATCAAAGCCCTGAC AGCCATCTGCGAGGAAATGGAAAAAGAGGGCAAGATCACCAAGATCGGACCCGAGAACCCCTACAACACC CCTGTGTTCGCCATCAAGAAGAAAGACAGCACCAAGTGGAGGAAACTGGTGGACTTCAGAGAGCTGAACA AGCGGACCCAGGACTTCTGGGAGGTGCAGCTGGGCATCCCTCACCCTGCTGGCCTGAAGAAAAAGAAAAG CGTGACCGTGCTGGCTGTGGGAGATGCCTACTTCAGCGTGCCTCTGGACGAGGGCTTCCGGAAGTACACA GCCTTCACCATCCCCAGCACCAACAACGAGACACCTGGCATCAGATACCAGTACAACGTGCTGCCTCAGG GCTGGAAAGGCAGCCCTGCCATCTTCCAGTGCAGCATGACCAGAATCCTGGAACCCTTCAGAGCCAAGAA CCCTGAGATCGTGATCTACCAGTATATGGCTGCCCTCTACGTGGGCAGCGACCTGGAAATCGGACAGCAC AGAGCCAAAATCGAAGAACTCCGCGAGCACCTGCTGAAGTGGGGATTCACCACCCCTGACAAGAAGCACC AGAAAGAGCCTCCCTTCCTGTGGATGGGCTACGAGCTGCACCCTGACAAGTGGACCGTGCAGCCCATCCA GCTGCCAGAGAAGGACTCCTGGACCGTGAACGACATCCAGAAACTGGTCGGCAAGCTGAACTGGGCCAGC CAGATCTACCCTGGCATCAAAGTCAGACAGCTGTGTAAGCTGCTGAGGGGAGCCAAAGCACTGACCGACA TCGTGCCTCTGACAGAAGAAGCCGAGCTGGAACTGGCCGAGAACAGAGAGATCCTGAAAGAACCCGTGCA CGGAGTGTACTACGACCCCTCCAAGGACCTGATTGCCGAGATCCAGAAACAGGGACACGACCAGTGGACC TACCAGATCTATCAGGAACCTTTCAAGAACCTGAAAACAGGCAAGTACGCCAAGATGCGGACAGCCCACA CCAACGACGTGAAGCAGCTGACCGAAGCCGTGCAGAAAATCGCCATGGAAAGCATCGTGATCTGGGGAAA GACACCCAAGTTCAGGCTGCCCATCCAGAAAGAGACATGGGAAACCTGGTGGACCGACTACTGGCAGGCC ACCTGGATTCCCGAGTGGGAGTTCGTGAACACCCCACCCCTGGTGAAGCTGTGGTATCAGCTGGAAAAGG ACCCTATCGCTGGCGTGGAGACATTCTACGTGGCTGGAGCTGCCAACAGAGAGACAAAGCTGGGCAAGGC TGGCTACGTGACCGACAGAGGCAGACAGAAAATCGTGAGCCTGACCGAAACCACCAACCAGAAAACAGCC CTGCAGGCCATCTATCTGGCACTGCAGGACAGCGGAAGCGAGGTGAACATCGTGACAGCCAGCCAGTATG CCCTGGGCATCATCCAGGCCCAGCCTGACAAGAGCGAGAGCGAGCTGGTGAACCAGATCATCGAGCAGCT GATCAAGAAAGAACGGGTGTACCTGAGCTGGGTGCCAGCCCACAAGGGCATCGGAGGGAACGAGCAGGTG GACAAGCTGGTGTCCAGCGGAATCCGGAAGGTGCTGTTCCTGGACGGCATCGATAAAGCCCAGGAAGAGC ACGAGAAGTACCACAGCAATTGGAGAGCCATGGCCAGCGACTTCAACCTGCCTCCCGTGGTGGCCAAAGA AATCGTGGCCAGCTGCGACCAGTGCCAGCTGAAAGGCGAGGCCATGCACGGACAGGTGGACTGCTCCCCT GGCATCTGGCAGCTGGCATGCACCCACCTGGAAGGCAAGATCATTCTGGTGGCCGTGCACGTGGCCAGCG GATACATCGAAGCCGAAGTGATCCCTGCCGAGACAGGGCAGGAAACAGCCTACTTCATCCTGAAGCTGGC TGGCAGATGGCCTGTGAAGGTGATCCACACAGCCAACGGCAGCAACTTCACCTCTGCTGCCGTGAAGGCT GCCTGTTGGTGGGCTGGCATTCAGCAGGAATTTGGCATCCCCTACAATCCCCAGTCTCAGGGAGTGGTGG CCAGCATGAACAAAGAGCTGAAGAAGATCATCGGACAGGTCAGGGATCAGGCCGAGCACCTGAAAACTGC CGTCCAGATGGCCGTGTTCATCCACAACTTCAAGCGGAAGGGAGGGATCGGAGGGTACTCTGCTGGCGAG CGGATCATCGACATCATTGCCACCGATATCCAGACCAAAGAGCTGCAGAAACAGATCATCAAGATCCAGA ACTTCAGGGTGTACTACAGGGACAGCAGGGACCCCATCTGGAAGGGACCTGCCAAGCTGCTGTGGAAAGG CGAAGGAGCCGTCGTCATCCAGGACAACAGCGACATCAAGGTGGTGCCCAGACGGAAGGTGAAAATCATC AAGGACTACGGCAAACAGATGGCTGGAGCCGACTGTGTCGCTGGCAGGCAGGACGAGGAC SEQ ID NO: 8 (Mos2.Gag-Pol DNA) ATGGGAGCCAGAGCCAGCATCCTGCGAGGAGGGAAGCTGGACAAGTGGGAGAAGATCAGGCTGAGGCCTG GAGGGAAGAAACACTACATGCTGAAGCACCTGGTCTGGGCCAGCAGAGAGCTGGAACGGTTTGCCCTCAA TCCTGGCCTGCTGGAAACCAGCGAGGGCTGCAAGCAGATCATCAAGCAGCTGCAGCCTGCCCTGCAGACA GGCACCGAGGAACTGCGGAGCCTGTTCAACACCGTGGCCACCCTGTACTGCGTGCATGCCGAGATCGAAG TGAGGGACACCAAAGAAGCCCTGGACAAGATCGAGGAAGAGCAGAACAAGAGCCAGCAGAAAACCCAGCA GGCCAAAGAAGCCGACGGCAAGGTCTCCCAGAACTACCCCATCGTGCAGAACCTGCAGGGACAGATGGTG CACCAGCCCATCAGCCCTCGGACACTGAATGCCTGGGTGAAGGTGATCGAGGAAAAGGCCTTCAGCCCTG AGGTGATCCCCATGTTCACAGCCCTGAGCGAGGGAGCCACACCCCAGGACCTGAACACCATGCTGAACAC CGTGGGAGGGCACCAGGCTGCCATGCAGATGCTGAAGGACACCATCAACGAGGAAGCTGCCGAGTGGGAC AGGCTGCACCCTGTGCACGCTGGACCTGTGGCTCCTGGCCAGATGAGAGAGCCCAGAGGCAGCGATATTG CTGGCACCACCTCCAATCTGCAGGAACAGATCGCCTGGATGACCAGCAACCCTCCCATCCCTGTGGGAGA CATCTACAAGCGGTGGATCATCCTGGGACTGAACAAGATCGTGCGGATGTACAGCCCTACCTCCATCCTG GACATCAAGCAGGGACCCAAAGAGCCTTTCAGGGACTACGTGGACCGGTTCTTCAAGACCCTGAGAGCCG AGCAGGCCACCCAGGACGTGAAGAACTGGATGACCGACACCCTGCTGGTGCAGAACGCCAACCCTGACTG CAAGACCATCCTGAGAGCCCTGGGACCTGGAGCCACCCTGGAAGAGATGATGACAGCCTGCCAGGGAGTG GGAGGACCCTCTCACAAGGCTAGGGTGCTGGCCGAGGCCATGAGCCAGACCAACAGCACCATCCTGATGC AGCGGAGCAACTTCAAGGGCAGCAAGCGGATCGTGAAGTGCTTCAACTGTGGCAAAGAGGGACACATTGC CAGAAACTGTAGGGCACCCAGGAAGAAAGGCTGCTGGAAGTGCGGAAAAGAAGGCCACCAGATGAAGGAC TGCACCGAGAGGCAGGCCAACTTCCTGGGCAAGATCTGGCCTAGCCACAAGGGCAGACCTGGCAACTTCC TGCAGAGCAGACCCGAGCCCACCGCTCCTCCAGCCGAGAGCTTCCGGTTCGAGGAAACCACCCCTGCTCC CAAGCAGGAACCTAAGGACAGAGAGCCTCTGACCAGCCTGAGAAGCCTGTTCGGCAGCGACCCTCTGAGC CAGATGGCTCCCATCTCCCCTATCGAGACAGTGCCTGTGAAGCTGAAGCCTGGCATGGACGGACCCAAGG TGAAACAGTGGCCTCTGACCGAGGAAAAGATCAAAGCCCTGGTGGAGATCTGTACCGAGATGGAAAAAGA GGGCAAGATCAGCAAGATCGGACCCGAGAACCCCTACAACACCCCTATCTTCGCCATCAAGAAGAAAGAC AGCACCAAGTGGAGGAAACTGGTGGACTTCAGAGAGCTGAACAAGCGGACCCAGGACTTCTGGGAGGTGC AGCTGGGCATCCCTCACCCTGCTGGCCTGAAGAAAAAGAAAAGCGTGACCGTGCTGGCCGTGGGAGATGC CTACTTCAGCGTGCCTCTGGACGAGGACTTCAGAAAGTACACAGCCTTCACCATCCCCAGCATCAACAAC GAGACACCTGGCATCAGATACCAGTACAACGTGCTGCCTCAGGGATGGAAGGGCTCTCCTGCAATCTTCC AGAGCAGCATGACCAAGATCCTGGAACCCTTCCGGAAGCAGAACCCTGACATCGTGATCTACCAGTACAT GGCAGCCCTGTACGTCGGCAGCGACCTGGAAATCGGACAGCACCGGACCAAGATCGAAGAACTCAGGCAG CACCTGCTGCGGTGGGGATTCACCACCCCTGACAAGAAGCACCAGAAAGAGCCTCCCTTCCTGTGGATGG GCTACGAGCTGCACCCAGACAAGTGGACCGTGCAGCCCATCGTGCTGCCTGAGAAGGACTCCTGGACCGT GAACGACATCCAGAAACTGGTCGGCAAGCTGAACTGGGCCAGCCAGATCTACGCTGGCATCAAAGTGAAG CAGCTGTGTAAGCTCCTGAGAGGCACCAAAGCCCTGACCGAGGTGGTGCCACTGACAGAGGAAGCCGAGC TGGAACTGGCCGAGAACAGAGAGATCCTGAAAGAACCCGTGCACGGAGTGTACTACGACCCCAGCAAGGA CCTGATTGCCGAGATCCAGAAGCAGGGACAGGGACAGTGGACCTACCAGATCTACCAGGAACCCTTCAAG AACCTGAAAACAGGCAAGTACGCCAGGATGAGGGGAGCCCACACCAACGACGTCAAACAGCTGACCGAAG CCGTGCAGAAGATCGCCACCGAGAGCATCGTGATTTGGGGAAAGACACCCAAGTTCAAGCTGCCCATCCA GAAAGAGACATGGGAGGCCTGGTGGACCGAGTACTGGCAGGCCACCTGGATTCCCGAGTGGGAGTTCGTG AACACCCCACCCCTGGTGAAGCTGTGGTATCAGCTGGAAAAAGAACCCATCGTGGGAGCCGAGACATTCT ACGTGGCTGGAGCTGCCAACAGAGAGACAAAGCTGGGCAAGGCTGGCTACGTGACCGACAGAGGCAGGCA GAAAGTGGTGTCCCTGACCGATACCACCAACCAGAAAACAGCCCTGCAGGCCATCCACCTGGCTCTGCAG GACTCTGGCCTGGAAGTGAACATCGTGACAGCCAGCCAGTATGCCCTGGGCATCATTCAGGCACAGCCTG ACAAGAGCGAGAGCGAGCTGGTGTCTCAGATCATTGAGCAGCTGATCAAGAAAGAAAAGGTGTACCTGGC CTGGGTGCCAGCCCACAAGGGGATCGGAGGGAACGAGCAGGTGGACAAGCTGGTGTCCAGGGGCATCCGG AAGGTGCTGTTTCTGGACGGCATCGACAAAGCCCAGGAAGAGCACGAGAAGTACCACAGCAATTGGAGAG CCATGGCCAGCGAGTTCAACCTGCCTCCCATCGTGGCCAAAGAAATCGTGGCCTCTTGCGACAAGTGCCA GCTGAAAGGCGAGGCCATTCACGGACAGGTGGACTGCAGCCCAGGCATCTGGCAGCTGGCCTGCACCCAC CTGGAAGGCAAGGTGATCCTGGTGGCCGTGCACGTGGCCTCTGGATACATCGAAGCCGAAGTGATCCCTG CCGAGACAGGCCAGGAAACAGCCTACTTCCTGCTGAAGCTGGCTGGCAGGTGGCCTGTGAAAACCATCCA CACAGCCAACGGCAGCAACTTCACCTCTGCCACCGTGAAGGCTGCCTGTTGGTGGGCTGGCATTAAGCAG GAATTTGGCATCCCCTACAACCCTCAGTCTCAGGGAGTGGTGGCCTCCATCAACAAAGAGCTGAAGAAGA TCATCGGACAGGTCAGGGATCAGGCCGAGCATCTGAAAACAGCCGTCCAGATGGCCGTGTTCATCCACAA CTTCAAGCGGAAGGGAGGGATCGGAGAGTACTCTGCTGGCGAGAGGATCGTGGACATTATCGCCAGCGAT ATCCAGACCAAAGAACTGCAGAAGCAGATCACAAAGATCCAGAACTTCAGGGTGTACTACAGGGACAGCA GAGATCCCCTGTGGAAGGGACCTGCCAAGCTGCTGTGGAAAGGCGAAGGAGCCGTCGTCATCCAGGACAA CAGCGACATCAAGGTGGTGCCCAGACGGAAGGCCAAGATCATCAGAGACTACGGCAAACAGATGGCTGGC GACGACTGCGTCGCCTCTAGGCAGGACGAGGAC

REFERENCES

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What is claimed is:
 1. A method of inducing an immune response against a human immunodeficiency virus (HIV) in an HIV-infected human subject undergoing antiretroviral therapy (ART), the method comprising: (i) administering to the human subject a primer vaccine comprising an immunogenically effective amount of one or more first adenovirus 26 (Ad26) vectors encoding one or more mosaic HIV antigens comprising the amino acid sequences selected from the group consisting of SEQ ID NOs: 1, 3, and 4, and a pharmaceutically acceptable carrier; and (ii) administering to the human subject a booster vaccine comprising an immunogenically effective amount of one or more modified vaccinia ankara (MVA) vectors encoding one or more mosaic HIV antigens comprising the amino acid sequences selected from the group consisting of SEQ ID NOs: 1-4, wherein the subject started ART at least four weeks prior to initial administration of the primer vaccine.
 2. The method according to claim 1, wherein the immunogenically effective amount of the Ad26 vectors encoding one or more mosaic HIV antigens of SEQ ID NOs: 1, 3, and 4 consists of three Ad26 vectors of which a first Ad26 vector encodes mosaic HIV antigen of SEQ ID NO: 1, a second Ad26 vector encodes mosaic HIV antigen of SEQ ID NO: 3, and a third Ad26 vector encodes mosaic HIV antigen of SEQ ID NO:
 4. 3. The method according to claim 2, wherein the first, second, and third Ad26 vectors are administered at a total dose of about 5×10¹⁰ viral particles (vp).
 4. The method according to claim 1, wherein the immunogenically effective amount of the MVA vectors encoding one or more mosaic HIV antigens of SEQ ID NOs: 1-4 consists of two MVA vectors of which a first MVA vector encodes mosaic HIV antigens of SEQ ID NOs: 1 and 3, and a second MVA vector encodes mosaic HIV antigens of SEQ ID NOs: 2 and
 4. 5. The method according to claim 4, wherein the first and second MVA vectors are administered at a total dose of about 1×10⁸ plaque forming units (pfu).
 6. The method of claim 1, wherein the primer vaccine is re-administered at about 10-14 weeks after the primer vaccine is initially administered; the booster vaccine is first administered at about 22-26 weeks after the primer vaccine is initially administered; and the booster vaccine is re-administered at about 46-50 weeks after the primer vaccine is initially administered.
 7. The method according to claim 6, wherein the primer vaccine is re-administered at about 12 weeks after the primer vaccine is initially administered; the booster vaccine is first administered at about 24 weeks after the primer vaccine is initially administered; and the booster vaccine is re-administered at about 48 weeks after the primer vaccine is initially administered.
 8. The method according to claim 1, wherein the ART is discontinued at about 10-14 weeks after the last booster vaccine is administered.
 9. The method according to claim 8, wherein the subject is administered an activator of latent HIV reservoir after discontinuing ART.
 10. The method according to claim 1, wherein the human subject initiated ART during acute HIV infection.
 11. The method of claim 1, wherein the ART comprises at least one selected from the group consisting of a nucleoside reverse transcriptase inhibitor, a non-nucleotide reverse transcriptase inhibitor, a protease inhibitor, an integrase inhibitor, a fusion inhibitor, an entry inhibitor and a chemokine receptor antagonist.
 12. A method of inducing an immune response against a human immunodeficiency virus (HIV) in an HIV-infected human subject undergoing antiretroviral therapy (ART), the method comprising: (i) administering to the human subject a primer vaccine comprising an immunogenically effective amount of a first adenovirus 26 (Ad26) vector encoding a mosaic HIV antigen of SEQ ID NO: 1, a second Ad26 vector encoding a mosaic HIV antigen of SEQ ID NO: 3, and a third Ad26 vector encoding a mosaic HIV antigen of SEQ ID NO: 4, and a pharmaceutically acceptable carrier; and administering to the human subject a booster vaccine comprising an immunogenically effective amount of a first modified vaccinia ankara (MVA) vector encoding mosaic HIV antigens of SEQ ID NOs: 1 and 3, and a second MVA vector encoding mosaic HIV antigens of SEQ ID NOs: 2 and 4, and a pharmaceutically acceptable carrier, wherein the primer vaccine is re-administered at about 10-14 weeks after the primer vaccine is initially administered; the booster vaccine is first administered at about 22-26 weeks after the primer vaccine is initially administered; and the booster vaccine is re-administered at about 46-50 weeks after primer vaccine is initially administered; and wherein the human subject initiated ART during acute HIV infection and the human subject has sustained viremic control defined as plasma HIV RNA of less than 50 copies per ml for at least 48 weeks prior to the initial administration of the primer vaccine, optionally with one or more blips of plasma HIV RNA greater than 50 copies/ml to less than 20 copies/ml, provided that screening immediately prior to initial administration of the primer vaccine is less than 50 copies per ml.
 13. The method according to claim 12, wherein the first, second, and third Ad26 vectors are at a ratio of about 2:1:1, respectively; and the first and second MVA vectors are at a ratio of about 1:1, respectively.
 14. The method according to claim 12, wherein the first, second, and third Ad26 vectors are administered at a total dose of about 5×10¹⁰ vp; and the first and second MVA vectors are administered at a total dose of about 1×10⁸ pfus.
 15. The method according to claim 12, wherein the primer vaccine is re-administered at about 12 weeks after the primer vaccine is initially administered, the booster vaccine is first administered at about 24 weeks after the primer vaccine is initially administered, and the booster vaccine is re-administered at about 48 weeks after the primer vaccine is initially administered.
 16. The method according to claim 12, wherein the ART is discontinued at about 10-14 weeks after the last booster vaccine is administered.
 17. The method according to claim 16, wherein the subject is administered an activator of latent HIV reservoir comprising a histone deacetylase inhibitor after discontinuing ART.
 18. The method according to claim 12, wherein the ART comprises at least one selected from the group consisting of a nucleoside reverse transcriptase inhibitor, a non-nucleotide reverse transcriptase inhibitor, a protease inhibitor, an integrase inhibitor, a fusion inhibitor, an entry inhibitor and a chemokine receptor antagonist.
 19. The method according to claim 12, wherein the primer vaccine and the booster vaccine are administered via intramuscular injection.
 20. The method according to claim 12, wherein administration of the primer vaccine and booster vaccine induces an immune response against multiple clades of HIV in the subject. 